The final 2018 data tables were updated on 5/22/2019 for Maryland’s all-time record precipitation year. With the release of the “Maryland and Delaware Climatological Data Annual Summary” by the National Centers for Environmental Information (NCEI), in conjunction with data from the Applied Climate Information System database (ACIS) from the NOAA Regional Climate Centers, these final numbers could finally be verified. Not only did Maryland set its all-time annual total (the 84.56″ at Catonsville was investigated and verifed by the State Climate Extremes Committee) but Washington, DC did also (74.10″ at Dalecarlia Reservoir), both shown in the listings below.   

Updated data tables on 2/4/2019 are found below with a few more updates of Coop station totals (including Sines Deep Creek, Patuxent River NAS, Savage River Dam, and Snow Hill) and a CoCoRaHS station or two due to new data coming in. This will likely be the final revision for 2018. There were 3 Coop and 14 CoCoRaHS stations that exceeded the existing official Maryland record of 76.52″ for calendar-year precipitation total. 

Please note that some of the original narrative, below, has been superseded by the data tables below the narrative.

Narrative originally published 12/13/2018:

It has been a very wet year across most of Maryland in 2018, with numerous locations already having set their annual precipitation records. It is up to the State Climate Extremes Committee (SCEC) to verify a state record, which they will likely have to do for this year’s data. The official Maryland record in a calendar year is currently 76.52″, set at Towson in 1971, according to the National Centers for Environmental Information, the nation’s climate archive. For 2018, as far as stations within the National Weather Service’s Cooperative Observer Program, the current leader is “Mechanicsville 5 NE”, located in southern Maryland’s St. Mary’s County, which, as of today, has recorded 76.45″, just 0.07″ short of the record. Several other stations are not far behind. In addition to the Coop Network, the Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS) is an additional volunteer network of observers that also measures precipitation. Two CoCoRaHS stations have actually exceeded the state record and several others are close, something that the SCEC will have to judge as official once the year ends.  Below are the current top amounts recorded in each network:

National Weather Service Coop Network (all stations with continuous data)

CoCoRaHS Network (only stations >60″)

Maryland-Precipitation-Totals-2018_Final-report-of-2019-05-22

Please click the above link (red text) for a pdf version of the table data that is found below. 

Jeff

Cover Photo of historic Ellicott City flooding is courtesy of the USA Today.