Live/247 Rank/Maryland

Maryland 24/7 Rank

Every station in Maryland ranked by its 247 score out of 100: how reliably it reports, how accurate its readings are against a reference station, how they pass their checks and how they stand against the forecast, over the last seven days.

564 stations ranked26.4% sent every report dueranked October 4, 2026page 1 of 3Maryland instrumentsMaryland weather

A station is ranked once its week holds enough reports to measure: 12, or 3 days for a gauge that reports once a day. Of the 564 ranked here, 559 have a page of their own; the rest are platforms heard here that have not yet reported enough to be listed.

Every ranked station, first to last

1stLast

Each rank wears its colour: first in its state in bright green, last in deep red, and every rank between mixed along the band.

How they reported this week

The days behind it

7 days30 days90 days

every report90 to 99%under 90%

Every station, ranked

Rank	Station	Score	Network	County	Received	Reports	Arrives in	Longest silence
1	GaithersburgGAI	100.0	Airport	Montgomery	100%	168 of 168	9 min	82 min
2	MillersMLLM2	100.0	Cooperative	Carroll	100%	7 of 7	58 min	24 h
3	Damascus 3 SSWDMAM2	100.0	Cooperative	Montgomery	100%	7 of 7	79 min	24 h
4	Nepp Site At ReisterstownRSTM2	100.0	Gauge	Baltimore	100%	7 of 7	81 min	24 h
5	Bishopville 3.1 EMD-WR-4	100.0	Volunteer	Worcester	100%	3 of 3	26 min	24 h
6	Deale 0.9 SEMD-AA-43	100.0	Volunteer	Anne Arundel	100%	3 of 3	26 min	24 h
6	Frederick 2.7 NMD-FR-40	100.0	Volunteer	Frederick	100%	3 of 3	26 min	24 h
6	Frederick 8.4 ENEMD-FR-47	100.0	Volunteer	Frederick	100%	3 of 3	26 min	24 h
6	Middletown 0.3 NMD-FR-50	100.0	Volunteer	Frederick	100%	3 of 3	26 min	24 h
6	Sykesville 2.2 SSEMD-HW-44	100.0	Volunteer	Howard	100%	3 of 3	26 min	24 h
6	North Potomac 3.8 NMD-MG-128	100.0	Volunteer	Montgomery	100%	3 of 3	26 min	24 h
6	Damascus 1.0 SMD-MG-156	100.0	Volunteer	Montgomery	100%	3 of 3	26 min	24 h
6	California 2.1 WMD-SM-27	100.0	Volunteer	St. Marys	100%	3 of 3	26 min	24 h
6	Berlin 3.9 SEMD-WR-31	100.0	Volunteer	Worcester	100%	3 of 3	26 min	24 h
15	Queenstown 2.6 SMD-QA-6	100.0	Volunteer	Queen Anne's	100%	3 of 3	26 min	24 h
16	Catonsville 2.8 NNWMD-BL-70	100.0	Volunteer	Baltimore	100%	3 of 3	26 min	24 h
16	New Windsor 0.1 ESEMD-CR-39	100.0	Volunteer	Carroll	100%	3 of 3	26 min	24 h
16	Sykesville 2.6 SEMD-HW-12	100.0	Volunteer	Howard	100%	3 of 3	26 min	24 h
16	Chestertown 0.7 NNWMD-KN-12	100.0	Volunteer	Kent	100%	3 of 3	26 min	24 h
16	Gaithersburg 2.8 NNEMD-MG-144	100.0	Volunteer	Montgomery	100%	3 of 3	26 min	24 h
16	Takoma Park 0.6 NNWMD-MG-42	100.0	Volunteer	Montgomery	100%	3 of 3	26 min	24 h
16	Greenbelt 0.7 NNEMD-PG-106	100.0	Volunteer	Prince Georges	100%	3 of 3	26 min	24 h
16	Hagerstown 4.1 NNWMD-WH-19	100.0	Volunteer	Washington	100%	3 of 3	26 min	24 h
24	Norrisville 0.6 WSWMD-HR-23	100.0	Volunteer	Harford	100%	3 of 3	26 min	25 h
25	Silver Spring 2.1 NNEMD-MG-109	100.0	Volunteer	Montgomery	100%	3 of 3	85 min	24 h
26	Arnold 1.6 NMD-AA-91	100.0	Volunteer	Anne Arundel	100%	3 of 3	85 min	2 days
27	Mount Airy 0.6 WSWMD-FR-61	100.0	Volunteer	Frederick	100%	3 of 3	86 min	24 h
27	Gaithersburg 2.4 EMD-MG-154	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	24 h
29	Severn 1.5 SSWMD-AA-51	100.0	Volunteer	Anne Arundel	100%	3 of 3	86 min	25 h
29	Silver Spring 6.4 NNEMD-MG-106	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	25 h
29	Olney 1.4 ENEMD-MG-78	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	25 h
32	Mechanicsville 3.8 NMD-SM-18	100.0	Volunteer	St. Marys	100%	3 of 3	86 min	27 h
32	MD-WH-27MD-WH-27	100.0	COCORAHS	-	100%	3 of 3	86 min	27 h
34	White Marsh 2.3 ESEMD-BL-25	100.0	Volunteer	Baltimore	100%	3 of 3	86 min	24 h
34	Chevy Chase 1.2 SWMD-MG-145	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	24 h
34	Beltsville 1.4 NNWMD-PG-82	100.0	Volunteer	Prince Georges	100%	3 of 3	86 min	24 h
34	Ridge 1.0 NMD-SM-1	100.0	Volunteer	St. Marys	100%	3 of 3	86 min	24 h
34	Hagerstown 1.0 ENEMD-WH-3	100.0	Volunteer	Washington	100%	3 of 3	86 min	24 h
39	Sandy Spring 1.6 WMD-MG-148	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	25 h
40	Severn 1.5 WMD-AA-99	100.0	Volunteer	Anne Arundel	100%	3 of 3	86 min	26 h
41	Elkton 7.0 NNWMD-CC-10	100.0	Volunteer	Cecil	100%	3 of 3	86 min	24 h
42	Hebron 3.6 WMD-WC-27	100.0	Volunteer	Wicomico	100%	3 of 3	86 min	2 days
43	Perry Hall 0.3 ENEMD-BL-69	100.0	Volunteer	Baltimore	100%	3 of 3	86 min	24 h
43	Eldersburg 0.9 EMD-CR-19	100.0	Volunteer	Carroll	100%	3 of 3	86 min	24 h
43	Taneytown 3.8 NEMD-CR-5	100.0	Volunteer	Carroll	100%	3 of 3	86 min	24 h
43	Laurel 1.9 NEMD-HW-58	100.0	Volunteer	Howard	100%	3 of 3	86 min	24 h
43	Norbeck 1.1 ESEMD-MG-5	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	24 h
43	Rossmoor 1.3 ESEMD-MG-55	100.0	Volunteer	Montgomery	100%	3 of 3	86 min	24 h
43	Charlotte Hall 3.6 ENEMD-SM-4	100.0	Volunteer	St. Marys	100%	3 of 3	86 min	24 h
43	Delmar 0.3 ESEMD-WC-26	100.0	Volunteer	Wicomico	100%	3 of 3	86 min	24 h
51	Laurel 1.3 NNEMD-HW-38	100.0	Volunteer	Howard	100%	3 of 3	86 min	25 h
52	Jefferson 1.6 SSEMD-FR-24	100.0	Volunteer	Frederick	100%	3 of 3	2.4 h	24 h
52	Grantsville 2.0 ESEMD-GR-15	100.0	Volunteer	Garrett	100%	3 of 3	2.4 h	24 h
54	Towson 0.8 SWMD-BL-16	100.0	Volunteer	Baltimore	100%	3 of 3	2.4 h	24 h
54	Long Green 0.6 SWMD-BL-9	100.0	Volunteer	Baltimore	100%	3 of 3	2.4 h	24 h
54	Mc Henry 4.8 SSEMD-GR-4	100.0	Volunteer	Garrett	100%	3 of 3	2.4 h	24 h
57	Kingsville 1.2 EMD-BL-28	100.0	Volunteer	Baltimore	100%	3 of 3	2.4 h	24 h
57	Jarrettsville 1.9 ESEMD-HR-28	100.0	Volunteer	Harford	100%	3 of 3	2.4 h	24 h
57	Montgomery Village 1.1 ENEMD-MG-138	100.0	Volunteer	Montgomery	100%	3 of 3	2.4 h	24 h
57	Parsonsburg 1.6 WNWMD-WC-9	100.0	Volunteer	Wicomico	100%	3 of 3	2.4 h	24 h
57	Ocean City 4.6 NNWMD-WR-28	100.0	Volunteer	Worcester	100%	3 of 3	2.4 h	24 h
62	Charlestown 0.4 WSWMD-CC-15	100.0	Volunteer	Cecil	100%	3 of 3	2.4 h	24 h
62	Columbia 1.9 NMD-HW-36	100.0	Volunteer	Howard	100%	3 of 3	2.4 h	24 h
64	Smithburg - Well WA BKSMWM2	99.9	Gauge	Washington	100%	168 of 168	11 min	62 min
65	AnnapolisNAK	99.9	Airport	Anne Arundel	100%	168 of 168	11 min	68 min
66	Centennial Branch AT Centennial LakeCBPM2	99.8	Gauge	Howard	100%	56 of 56	21 min	3 h
67	CedarvilleCVLM2	99.7	Gauge	Prince Georges	100%	168 of 168	12 min	60 min
67	Green RidgeGRDM2	99.7	Gauge	Allegany	100%	168 of 168	12 min	60 min
69	FrostburgFRSM2	99.7	Cooperative	Allegany	100%	7 of 7	3.1 h	24 h
70	Seneca Creek AT DawsonvilleDAWM2	99.7	Gauge	Montgomery	99.4%	167 of 168	11 min	2 h
70	Little Patuxent River AT GuilfordLPGM2	99.7	Gauge	Howard	99.4%	167 of 168	11 min	2 h
70	Piscataway Creek AT PiscatawayPSCM2	99.7	Gauge	Prince Georges	99.4%	167 of 168	11 min	2 h
73	Baltimore - Wash IntlBWI	99.7	Airport	Anne Arundel	99.4%	167 of 168	11 min	2 h
73	Salisbury RegionalSBY	99.7	Airport	Worcester	99.4%	167 of 168	11 min	2 h
75	PDFM2PDFM2	99.6	DCP	-	100%	7 of 7	3.2 h	24 h
76	Baltimore Inner HarborDMH	99.5	Airport	Baltimore City	100%	168 of 168	12 min	69 min
77	Powellville 3Wnw RawsPWLM2	99.5	Gauge	Wicomico	100%	168 of 168	13 min	60 min
78	Elkton 6.8 NMD-CC-18	99.5	Volunteer	Cecil	100%	3 of 3	3.4 h	24 h
78	Worton 3.9 NWMD-KN-4	99.5	Volunteer	Kent	100%	3 of 3	3.4 h	24 h
78	College Park 0.7 NEMD-PG-100	99.5	Volunteer	Prince Georges	100%	3 of 3	3.4 h	24 h
81	Linthicum 0.4 ENEMD-AA-35	99.5	Volunteer	Anne Arundel	100%	3 of 3	3.4 h	24 h
82	Severna Park 1.9 WMD-AA-66	99.5	Volunteer	Anne Arundel	100%	3 of 3	3.4 h	24 h
82	Nanjemoy 5.3 SMD-CH-38	99.5	Volunteer	Charles	100%	3 of 3	3.4 h	24 h
82	Gaithersburg 3.1 NEMD-MG-63	99.5	Volunteer	Montgomery	100%	3 of 3	3.4 h	24 h
82	Bowie 2.4 NNEMD-PG-46	99.5	Volunteer	Prince Georges	100%	3 of 3	3.4 h	24 h
86	Ocean City MuniOXB	99.5	Airport	Worcester	99.4%	167 of 168	12 min	2 h
87	Hagerstown RegionalHGR	99.4	Airport	Washington	99.4%	167 of 168	12 min	2 h
88	Pond Branch At Oregon RidgeORRM2	99.4	Gauge	Baltimore	98.8%	166 of 168	11 min	2 h
89	Nassawango Creek 5 NW Nassawango CreekNSWM2	99.4	Gauge	Worcester	98.8%	166 of 168	11 min	2 h
90	Grave Run AT BeckleysvilleBKYM2	99.4	Gauge	Baltimore	98.8%	166 of 168	11 min	2 h
91	School House Pond AT Upper MarlboroSHPM2	99.4	Gauge	Prince Georges	98.8%	166 of 168	11 min	2 h
92	Isle of Wight - BATIWBM2	99.3	Gauge	Worcester	99.4%	167 of 168	13 min	2 h
93	Unknown AT Leeland RoadLEEM2	99.2	Gauge	Prince Georges	98.8%	168 of 170	12 min	2 h
94	NAKNAK	99.1	DCP	-	100%	7 of 7	4.3 h	24 h
95	Suitland 2.1 SEMD-PG-43	99.1	Volunteer	Prince Georges	100%	3 of 3	4.4 h	24 h
96	Delmar 7.2 WMD-WC-31	99.1	Volunteer	Wicomico	100%	3 of 3	4.4 h	24 h
97	MechanicsvilleMECM2	99.0	Cooperative	St Marys	100%	7 of 7	4.3 h	24 h
98	AT WoodstockWOOM2	99.0	Gauge	Baltimore	99.2%	133 of 134	15 min	2.3 h
99	Tributary To Dorsey Run AT GE Retention PondCGWM2	98.9	Gauge	Howard	100%	168 of 168	16 min	65 min
99	LochleaLCHM2	98.9	Gauge	Baltimore City	100%	168 of 168	16 min	65 min
99	3 NE Liberty Reservoir/MayfieldMFEM2	98.9	Gauge	Baltimore	100%	168 of 168	16 min	65 min
102	Leonardtown - McIntosh RunLENM2	98.9	Gauge	St. Marys	100%	168 of 168	16 min	60 min
102	Patuxent River AT LaurelLPRM2	98.9	Gauge	Prince Georges	100%	168 of 168	16 min	60 min
104	BlackwaterBLWM2	98.9	Gauge	Dorchester	100%	168 of 168	16 min	67 min
104	Ellicott City - Hudson BranchECHM2	98.9	Gauge	Howard	100%	168 of 168	16 min	67 min
106	Cherry CreekCCMM2	98.9	Gauge	Garrett	100%	168 of 168	16 min	75 min
106	Churchville RainCRGM2	98.9	Gauge	Harford	100%	168 of 168	16 min	75 min
108	Clarksburg - Kingsley Env CenterCKPM2	98.9	Gauge	Montgomery	100%	168 of 168	16 min	75 min
108	Swanton - North Glade RunNGLM2	98.9	Gauge	Garrett	100%	168 of 168	16 min	75 min
108	Clarksburg - Ten Mile CreekTMPM2	98.9	Gauge	Montgomery	100%	168 of 168	16 min	75 min
111	Rocky Point Park - Black River TribBRTM2	98.9	Gauge	Baltimore	99.4%	167 of 168	15 min	2 h
112	Claiborne - Eastern BayCLNM2	98.9	Gauge	Talbot	99.4%	167 of 168	15 min	2 h
113	Pheasant Run - Patuxent Env RAWSPREM2	98.8	Gauge	Howard	100%	168 of 168	12 min	60 min
114	GreenbeltGBTM2	98.8	Gauge	Prince Georges	96.5%	28 of 29	16 min	6 h
115	Allview - Little Patuxent RiverSMPM2	98.7	Gauge	Howard	99.4%	167 of 168	15 min	2 h
116	Jones Falls Pumping StationJONM2	98.7	Gauge	Baltimore City	99.4%	167 of 168	15 min	2 h
117	Jones Falls At Union AvenueUNAM2	98.7	Gauge	Baltimore City	99.4%	167 of 168	16 min	2 h
118	Gwynns Falls At Gwynn Oak AvenueGFGM2	98.7	Gauge	Baltimore	99.4%	167 of 168	16 min	1.7 h
119	Norrisville RainNRGM2	98.7	Gauge	Harford	99.4%	167 of 168	16 min	1.8 h
119	Whiteford RainWRGM2	98.7	Gauge	Harford	99.4%	167 of 168	16 min	1.8 h
121	Baisman Run AT BroadmoorBRMM2	98.7	Gauge	Baltimore	99.4%	167 of 168	16 min	2 h
121	Back Branch 3 NE Brown Landfill/MellowwoodBRNM2	98.7	Gauge	Prince Georges	99.4%	167 of 168	16 min	2 h
121	Susquehanna AT Conowingo DamCNWM2	98.7	Gauge	Harford	99.4%	167 of 168	16 min	2 h
121	MillersvilleMLRM2	98.7	Gauge	Anne Arundel	99.4%	167 of 168	16 min	2 h
121	Owings MillsONGM2	98.7	Gauge	Baltimore	99.4%	167 of 168	16 min	2 h
121	Plumtree Run AT Bel AirPTRM2	98.7	Gauge	Harford	99.4%	167 of 168	16 min	2 h
121	Gwynns Falls AT Villa NovaVNVM2	98.7	Gauge	Baltimore	99.4%	167 of 168	16 min	2 h
128	Bennett Creek AT Park MillsPMBM2	98.7	Gauge	Frederick	99.4%	167 of 168	16 min	2 h
129	Beaverdam Run AT CockeysvilleCKYM2	98.7	Gauge	Baltimore	99.4%	167 of 168	16 min	2 h
129	Union MillsUNWM2	98.7	Gauge	Carroll	99.4%	167 of 168	16 min	2 h
131	Dickerson 6.6 SWMD-MG-103	98.6	Volunteer	Montgomery	100%	3 of 3	5.4 h	25 h
131	Poolesville 5.4 WMD-MG-120	98.6	Volunteer	Montgomery	100%	3 of 3	5.4 h	25 h
133	Cresaptown-Bel Air 0.9 SSEMD-AL-2	98.6	Volunteer	Allegany	100%	3 of 3	5.4 h	24 h
134	North Laurel 1.5 ESEMD-HW-21	98.6	Volunteer	Howard	100%	3 of 3	5.4 h	24 h
135	Silver Spring 4.2 NMD-MG-137	98.6	Volunteer	Montgomery	100%	3 of 3	5.4 h	24 h
136	Kensington 0.1 WMD-MG-40	98.6	Volunteer	Montgomery	100%	3 of 3	5.4 h	25 h
137	Andrews AFBADW	98.6	Airport	Prince Georges	98.8%	166 of 168	15 min	2 h
138	Antietam National BattlefieldANBM2	98.5	Gauge	Washington	100%	168 of 168	18 min	60 min
139	Piney Point - St George CreekSGSM2	98.5	Gauge	St. Marys	99.4%	167 of 168	17 min	2 h
140	Columbia - Little Patuxent RiverCSEM2	98.5	Gauge	Howard	98.8%	166 of 168	16 min	2 h
141	Soper Branch at HyattstownHYAM2	98.5	Gauge	Montgomery	98.8%	166 of 168	16 min	2 h
141	Dickerson - Monocacy RiverMRDM2	98.5	Gauge	Frederick	98.8%	166 of 168	16 min	2 h
141	Potomac River AT Point of RocksPORM2	98.5	Gauge	Frederick	98.8%	166 of 168	16 min	2 h
141	Patuxent River AT UnityPRUM2	98.5	Gauge	Montgomery	98.8%	166 of 168	16 min	2 h
141	Susquehanna RAWSSSQM2	98.5	Gauge	Harford	98.8%	166 of 168	16 min	2 h
146	Western Run AT Western RunWRWM2	98.4	Gauge	Baltimore	98.8%	166 of 168	16 min	2 h
147	Winters Run AT BensonBENM2	98.2	Gauge	Harford	98.2%	165 of 168	16 min	2 h
147	Little Seneca Creek at BrinkBIKM2	98.2	Gauge	Montgomery	98.2%	165 of 168	16 min	2 h
147	Patuxent River 3 W BowieBOWM2	98.2	Gauge	Prince Georges	98.2%	165 of 168	16 min	2 h
147	Piney Run AT DoverDVRM2	98.2	Gauge	Baltimore	98.2%	165 of 168	16 min	2 h
147	Little Seneca Creek near GermantownGMNM2	98.2	Gauge	Montgomery	98.2%	165 of 168	16 min	2 h
147	West Branch Herring Run AT IdlewyldeIDLM2	98.2	Gauge	Baltimore	98.2%	165 of 168	16 min	2 h
147	Unnamed Tributary AT Lake Arbor TailwaterLKDM2	98.2	Gauge	Prince Georges	98.2%	165 of 168	16 min	2 h
147	Prince Frederick - Well CA DB 47PFWM2	98.2	Gauge	Calvert	98.2%	165 of 168	16 min	2 h
155	Bel Air Acres 2SW - Winters RunWRBM2	98.2	Gauge	Harford	98.2%	165 of 168	16 min	3 h
156	Assateague IslandASTM2	98.1	Gauge	Worcester	100%	168 of 168	20 min	60 min
157	Timonium 0.2 NEMD-BL-52	98.1	Volunteer	Baltimore	100%	3 of 3	6.4 h	24 h
157	Adamstown 0.7 ESEMD-FR-23	98.1	Volunteer	Frederick	100%	3 of 3	6.4 h	24 h
159	Hamilton 0.3 NEMD-BC-1	98.1	Volunteer	Baltimore City	100%	3 of 3	6.4 h	24 h
160	Odenton 1.0 NMD-AA-65	98.1	Volunteer	Anne Arundel	100%	3 of 3	6.4 h	24 h
161	AbingdonABGM2	97.9	Gauge	Harford	100%	168 of 168	20 min	60 min
161	Paint Branch Tributary Near ColesvilleCLSM2	97.9	Gauge	Montgomery	100%	168 of 168	20 min	60 min
161	Whitemarsh Run AT FullertonFLRM2	97.9	Gauge	Baltimore	100%	168 of 168	20 min	60 min
161	Claremont - Herring RunHRSM2	97.9	Gauge	Baltimore City	100%	168 of 168	20 min	60 min
161	Honeygo Run AT White MarshWMHM2	97.9	Gauge	Baltimore	100%	168 of 168	20 min	60 min
166	Fallston - Winters Run BasinFALM2	97.9	Gauge	Harford	100%	168 of 168	21 min	70 min
167	Patapsco River AT ElkridgeERDM2	97.9	Gauge	Howard	100%	168 of 168	21 min	62 min
167	North Branch Potomac River AT LukeLUKM2	97.9	Gauge	Allegany	100%	168 of 168	21 min	62 min
169	Unnamed Tributary AT Largo Town Center DamLTCM2	97.9	Gauge	Prince Georges	97.2%	178 of 183	16 min	65 min
170	Little Falls AT Blue MountBLMM2	97.8	Gauge	Baltimore	97.0%	163 of 168	16 min	2 h
170	Marsh Run AT GrimesGRMM2	97.8	Gauge	Washington	97.0%	163 of 168	16 min	2 h
170	Cockeysville GroundwaterORWM2	97.8	Gauge	Baltimore	97.0%	163 of 168	16 min	2 h
170	Brunswick - Potomac RiverPRBM2	97.8	Gauge	Frederick	97.0%	163 of 168	16 min	2 h
174	Mattawoman Creek AT PomonkeyPOMM2	97.7	Gauge	Charles	99.4%	167 of 168	20 min	2 h
175	Patapsco River AT Ellicott CityELPM2	97.7	Gauge	Baltimore	99.4%	167 of 168	21 min	2 h
175	Town Creek AT OldtownOLTM2	97.7	Gauge	Allegany	99.4%	167 of 168	21 min	2 h
177	Patuxent River AT BristolBRIM2	97.7	Gauge	Anne Arundel	99.4%	167 of 168	21 min	2 h
177	Gwynns Falls AT DelightDELM2	97.7	Gauge	Baltimore	99.4%	167 of 168	21 min	2 h
177	CASSELMAN RIVER AT GrantsvilleGNTM2	97.7	Gauge	Garrett	99.4%	167 of 168	21 min	2 h
177	Long Quarter Branch AT LuthervilleLUTM2	97.7	Gauge	Baltimore	99.4%	167 of 168	21 min	2 h
177	Morgan Run AT LouisvilleMRLM2	97.7	Gauge	Carroll	99.4%	167 of 168	21 min	2 h
177	Brentwood - NB AnacostiaNBAM2	97.7	Gauge	Prince Georges	99.4%	167 of 168	21 min	2 h
177	Savage River AT Savage River DamSRDM2	97.7	Gauge	Garrett	99.4%	167 of 168	21 min	2 h
184	Patuxent River AT Laurel - 9th StreetPRNM2	97.7	Gauge	Prince Georges	96.7%	177 of 183	16 min	64 min
185	Tidal Anacostia River AT BladensburgBLDM2	97.7	Gauge	Prince Georges	96.1%	173 of 180	15 min	64 min
186	Nanticoke River AT SharptownSRPM2	97.6	Gauge	Wicomico	98.2%	165 of 168	19 min	2 h
187	Thayerville - Arrowhead RunARTM2	97.6	Gauge	Garrett	96.4%	162 of 168	16 min	2 h
187	Little Patuxent River AT SavageSAVM2	97.6	Gauge	Howard	96.4%	162 of 168	16 min	2 h
189	Cabin Branch Near BoydsBOYM2	97.5	Gauge	Montgomery	98.8%	166 of 168	21 min	2 h
189	Big Pipe Creek AT BrucevilleBRUM2	97.5	Gauge	Carroll	98.8%	166 of 168	21 min	2 h
189	ClarksburgCLKM2	97.5	Gauge	Montgomery	98.8%	166 of 168	21 min	2 h
189	Dead Run AT FranklintownDRFM2	97.5	Gauge	Baltimore	98.8%	166 of 168	21 min	2 h
189	Chesapeake Bay AT Havre De GraceHDGM2	97.5	Gauge	Harford	98.8%	166 of 168	21 min	2 h
194	Capitol Heights - Beaverdam CrekCHVM2	97.5	Gauge	Prince Georges	98.8%	166 of 168	21 min	2 h
194	East Branch Herbert Run AT ArbutusEBHM2	97.5	Gauge	Baltimore	98.8%	166 of 168	21 min	2 h
194	Licking Creek AT PectonvillePECM2	97.5	Gauge	Washington	98.8%	166 of 168	21 min	2 h
194	Scotts Level Branch AT RockdaleSLRM2	97.5	Gauge	Baltimore	98.8%	166 of 168	21 min	2 h
194	Thayerville - Deep Creek LakeTHYM2	97.5	Gauge	Garrett	98.8%	166 of 168	21 min	2 h
199	Paint Branch AT Hillandale - Powder MillHNDM2	97.5	Gauge	Prince Georges	92.8%	26 of 28	11 min	12 h
200	Hagerstown 1EHGCM2	97.4	Cooperative	Washington	100%	7 of 7	8 h	24 h
201	Monocacy River 5 SE BridgeportBDGM2	97.4	Gauge	Frederick	98.8%	166 of 168	21 min	2 h
201	BEAR CREEK AT FriendsvilleBRCM2	97.4	Gauge	Garrett	98.8%	166 of 168	21 min	2 h
203	Bynum Run AT Bel AirBABM2	97.4	Gauge	Harford	95.8%	161 of 168	16 min	3 h
204	Silver Spring 5.6 NMD-MG-71	97.2	Volunteer	Montgomery	100%	3 of 3	8.4 h	24 h
205	Sideling Hill Creek AT BellegroveBELM2	97.2	Gauge	Washington	98.2%	165 of 168	21 min	2 h
205	Gunpowder Falls AT ParktonPKTM2	97.2	Gauge	Baltimore	98.2%	165 of 168	21 min	2 h
207	Patapsco River AT CatonsvilleCTSM2	97.2	Gauge	Baltimore	98.2%	165 of 168	21 min	2 h
207	Gunpowder Falls AT GlencoeGCEM2	97.2	Gauge	Baltimore	98.2%	165 of 168	21 min	2 h
209	MitchellvilleMITM2	97.1	Gauge	Prince Georges	95.0%	213 of 224	16 min	65 min
210	Whitemarsh Run AT White MarshWHMM2	97.0	Gauge	Baltimore	97.6%	328 of 336	21 min	1.5 h
211	Ten Mile Creek AT BoydsBTMM2	97.0	Gauge	Montgomery	97.6%	164 of 168	21 min	2 h
212	Ten Mile Creek AT ClarksburgCTMM2	97.0	Gauge	Montgomery	97.6%	164 of 168	21 min	2 h
213	Potomac River AT Little FallsBRKM2	96.9	Gauge	Montgomery	100%	168 of 168	25 min	65 min
214	Catoctin Creek AT MiddletownMDLM2	96.9	Gauge	Frederick	100%	168 of 168	25 min	60 min
215	Nw Branch Anacostia River AT ColesvilleCLAM2	96.9	Gauge	Montgomery	100%	168 of 168	25 min	60 min
215	Hawlings River AT Sandy SpringSANM2	96.9	Gauge	Montgomery	100%	168 of 168	25 min	60 min
217	YOUGHIOGHENY RIVER AT FriendsvilleFRDM2	96.9	Gauge	Garrett	100%	168 of 168	25 min	75 min
218	Tonoloway Creek AT HancockHANM2	96.9	Gauge	Washington	100%	168 of 168	26 min	75 min
219	Birch Branch 1 N ShowellBBSM2	96.9	Gauge	Worcester	100%	168 of 168	26 min	77 min
219	Patuxent River AT BrightonBGHM2	96.9	Gauge	Howard	100%	168 of 168	26 min	77 min
219	Nerrs Water Quality Site Near RiversideLTQM2	96.9	Gauge	Harford	100%	168 of 168	26 min	77 min
222	Abingdon - Bynum RunBRAM2	96.9	Gauge	Harford	100%	168 of 168	26 min	77 min
222	KennedyvilleKENM2	96.9	Gauge	Kent	100%	168 of 168	26 min	77 min
224	Rock Hall 2.2 NNWMD-KN-10	96.7	Volunteer	Kent	100%	3 of 3	9.4 h	24 h
225	North Branch Potomac River 2 S CumberlandCBEM2	96.7	Gauge	Allegany	99.4%	167 of 168	26 min	2 h
225	North Branch Potomac River AT KitzmillerKITM2	96.7	Gauge	Garrett	99.4%	167 of 168	26 min	2 h
225	Swan Creek AT Swan CreekSWNM2	96.7	Gauge	Harford	99.4%	167 of 168	26 min	2 h
228	Gunpowder Falls AT HoffmanvilleGFHM2	96.7	Gauge	Baltimore	99.4%	167 of 168	26 min	2 h
228	Cattail Creek Near GlenwoodGLNM2	96.7	Gauge	Howard	99.4%	167 of 168	26 min	2 h
228	Manokin River 1.4 NE Manokin Branch near Princess AnneMNBM2	96.7	Gauge	Somerset	99.4%	167 of 168	26 min	2 h
228	RichardsmereRICM2	96.7	Gauge	Cecil	99.4%	167 of 168	26 min	2 h
228	Pocomoke River 1.3 E WillardsWLRM2	96.7	Gauge	Wicomico	99.4%	167 of 168	26 min	2 h
228	Georges Creek 1 N WesternportWSTM2	96.7	Gauge	Allegany	99.4%	167 of 168	26 min	2 h
234	St Marys River AT Great MillsGMRM2	96.7	Gauge	St Marys	99.4%	167 of 168	26 min	2 h
234	Zekiah Swamp Run AT NewtownZSRM2	96.7	Gauge	Charles	99.4%	167 of 168	26 min	2 h
236	Potomac River AT HancockHNKM2	96.5	Gauge	Washington	98.8%	166 of 168	26 min	2 h
236	YOUGHIOGHENY RIVER AT OaklandOAKM2	96.5	Gauge	Garrett	98.8%	166 of 168	26 min	2 h
236	Savage River 3 NW BloomingtonSRVM2	96.5	Gauge	Garrett	98.8%	166 of 168	26 min	2 h
236	North Branch Potomac River AT SteyerSTYM2	96.5	Gauge	Garrett	98.8%	166 of 168	26 min	2 h
240	Savage River 5 NW BartonBTNM2	96.5	Gauge	Garrett	98.8%	166 of 168	26 min	2 h
240	Chicamacomico Creek 1.6 E Chicamacomico River Near Salem MDCMCM2	96.5	Gauge	Dorchester	98.8%	166 of 168	26 min	2 h
240	Deer Creek AT DarlingtonDRLM2	96.5	Gauge	Harford	98.8%	166 of 168	26 min	2 h
240	Big Elk Creek AT Elk MillsEKMM2	96.5	Gauge	Cecil	98.8%	166 of 168	26 min	2 h
240	Long Green Creek AT Glen ArmGALM2	96.5	Gauge	Baltimore	98.8%	166 of 168	26 min	2 h
240	Greensboro - Choptank RiverGNBM2	96.5	Gauge	Caroline	98.8%	166 of 168	26 min	2 h
240	Youghiogheny River AT HoyesHOYM2	96.5	Gauge	Garrett	98.8%	166 of 168	26 min	2 h
240	Usgs Well Ca Fd 54LSWM2	96.5	Gauge	Calvert	98.8%	166 of 168	26 min	2 h
240	Patapsco River AT HollofieldPRHM2	96.5	Gauge	Baltimore	98.8%	166 of 168	26 min	2 h
240	Deer Creek AT Rocks State ParkRSPM2	96.5	Gauge	Harford	98.8%	166 of 168	26 min	2 h
240	Jones Falls 1.5 SW SorrentoSRTM2	96.5	Gauge	Baltimore	98.8%	166 of 168	26 min	2 h

How a station is ranked

The 247 Rank answers one question about a weather station: can its readings be relied on? A station has to deliver: its reports arrive when due, soon, without long silences. And its readings have to be right: close to a trusted station nearby, passing their checks, and in step with the weather the forecast and its neighbours confirm.

The 247 score

Storm Station's poller asks every network on its own schedule, around the clock, and keeps the time of every report it hears; the reference comparison and the forecast engine keep the rest. From the last seven days of that record each station is scored out of 100 on six parts, and its 247 score is their weighted mean:

Reports receivedweight 35The share of its scheduled reports received. A station that sends every 5 minutes is due 2,016 reports in a week; one that reports once a day is due 7. Each report is counted in a slot centred on the station's own report time, so a report a minute early or late is still on time, and the week ends an hour back, so a report still on its way is never counted missed.Full marks: 100% received. No marks: none received.
Arrivalweight 10The median time its reports took to arrive from the moment a reading was taken to the moment it reached Storm Station.Full marks: within 10 minutes, or a tenth of its schedule for a station that reports less often. No marks: an hour, or its whole schedule.
Continuityweight 10Its longest silence against its own schedule, so a daily gauge is not marked down for a day between reports.Full marks: a silence of 3 reports or less. No marks: 72 reports, falling evenly on a log scale between.
Accuracyweight 20How closely its temperature follows its reference station the nearest airport or climate reference station that reported within half an hour, up to 15 miles away, reading by reading. A steady offset is taken out, and where both heights are known only the offset beyond 3 F that the height difference does not explain is counted.Full marks: within 1.5 F, allowing 0.1 F more for each mile to the reference. No marks: 6.5 F beyond that.
Instrument checksweight 15The share of its readings that pass a check. For an airfield, the check the forecast engine runs the next day: each reading against the stations around it, as weather services check their own. For any other station, a reading 20 F or more from its reference fails, unless the two stand 3,000 ft or more apart.Full marks: none failed. No marks: 5% failed.
Forecast checkweight 10How closely its temperature matched Storm Station's forecast for the same hours, checked the next day, for every airfield the forecast engine scores. A station whose readings stray far from a forecast its neighbours confirm is one to doubt.Full marks: within 2 F on average. No marks: 8 F.

A part is scored once the week holds 24 readings or comparisons for it. A part that cannot be measured where a station stands counts at the middle of its state's measured stations, so the station is neither lifted nor sunk by it. A part measured nowhere in the state is left out, and the others carry its weight.

From score to rank

Each state's stations are ranked by their score, to the tenth. At an equal score the longer record comes first: a station that sent 2,016 of 2,016 reports has shown more than one that sent 7 of 7. Then the faster arrival, then the shorter silence. Ties on all of them share a rank, as a race is scored: three stations tied for third are all third, and the next is sixth.

A station is ranked once its week holds enough reports to measure: 12, or 3 days for a gauge that reports once a day. The rank is made again every day, so a station that falls silent or starts to read wrong drops, and one that recovers climbs back. Every page shows the same ranking: a station's rank here, in its state's list and on its own page come from one run, and a new run reaches them together. Each station's page shows its score part by part, with the figures behind each.

The same figures as data

/api/ranks for a state and /api/rank for one station, its score in parts; the developer page has every field.