Record Rain and Flooding of 2018

Severe Thunderstorm Threat From the Central Plains to the Northeast; Extreme HeatRisk for the East Coast

Strong to severe thunderstorms are possible from the central Plains to the Northeast through this evening. Widespread damaging winds are the primary threat but hail and a tornado or two is also possible. Extremely dangerous heat continues across the Eastern U.S. Warm overnight low temperatures will provide little to no relief. Read More >

Floods and Record Rainfall of 2018

(Page last updated February 11, 2019. Information is still being added to this page.)

All information presented here is preliminary and subject to future correction.
Click or tap on each header below to view additional information.

Overview

Baltimore & Washington Rainfall Statistics

Other Precip Totals

Flood Explorer Map

Significant Floods Recap

2018 was a memorable year for the Mid-Atlantic region, with some of the most frequent and persistent flooding observed in many years. While the severity of the flooding was not record breaking, the persistent nature of the rain kept conditions primed for flooding for about 75% of the year.

This page looks back at the significant and record-breaking rainfall from 2018, as well as the numerous flood events which occurred. Not all flood events are represented here; only the most significant are included.

Below is a map showing estimated rainfall (and melted snowfall) from the entire year. Click on it to make it larger:

PRELIMINARY RAINFALL RECORDS (with ending date):
Last updated after end of day 1/27/2019
2018 totals that did not set records are shown in purple. 2018 totals that did set records are in RED with the old record indicated. All information is preliminary and subject to correction.

	BWI - Baltimore, MD	DCA - Washington, DC/VA	IAD - Dulles, VA
1 day	7.62 (8/23/1933) 4.79 (7/21/2018) 10th	6.39 (8/23/1933) 4.00 (7/21/2018) 24th	10.67 (6/21/1972) 5.02 (7/21/2018) 5th
2 days	8.50 (8/13/1955) 5.49 (7/24/2018) 21st	9.41 (6/26/2006) 5.35 (7/22/2018) 21st	12.63 (6/22/1972) 5.10 (7/22/2018) 14th
3 days	10.98 (8/23/1933) 6.71 (7/23/2018) 8th	10.34 (6/27/2006) 5.41 (7/23/2018) 44th	13.18 (6/22/1972) 5.57 (7/23/2018) 19th
7 days	13.87 (8/18/1955) 12.14 (7/27/2018) 3rd	11.37 (6/28/2006) 8.20 (7/23/2018) 33rd	14.13 (6/23/1972) 7.76 (7/27/2018) 23rd
14 days	16.37 (7/28/2018) *old 15.93 (8/23/1955)*	14.09 (7/2/2006) 9.70 (7/30/2018) 77th	17.30 (7/3/1972) 10.66 (8/3/2018) 24th
30 days	18.90 (9/11/2011) 18.56 (8/14/2018) 2nd	17.45 (10/2/1934) 2018 not in top 100	18.78 (7/3/1972) 12.30 (8/1/2018) 60th
60 days	24.19 (9/13/2018) old 23.91 (10/1/2011)	23.37 (9/22/1934) 20.69 (9/14/2018) 35th	22.95 (7/1/1972) 20.33 (9/13/2018) 22nd
90 days	31.21 (8/7/2018) *old 27.01 (10/31/2011)*	28.85 (8/2/1886) 26.19 (10/14/2018) 23rd	27.71 (7/5/1972) 25.98 (10/14/2018) 17th
120 days	36.51 (9/9/2018) *old 32.78 (8/3/1889)*	34.45 (9/9/2018) *old 34.10 (7/26/1886)*	33.67 (9/9/2018) old 30.31 (7/9/1972)
180 days	48.39 (11/9/2018) *old 41.72 (8/14/1889)*	44.66 (11/7/2018) old 42.28 (8/1/1886)	44.15 (11/8/2018) old 40.58 (11/5/2003)
365 days ** these records are still being set as of 1/27/19	73.81 (1/27/2019)** old 65.95 (8/4/1889)	70.60 (7/26/1886) 68.60 (1/27/2019) 9th **	68.75 (1/27/2019)** old 66.57 (12/19/2003)
Calendar Year	71.82 (2018) *old 62.66 (2003)*	66.28 (2018) *old 61.33 (1889)*	66.74 (2018) old 65.67 (2003)
Wettest Calendar Months	16.73 (July 2018) old 11.03 (1889) 8.14 (Nov 2018) old 7.68 (1952)	7.57 (Nov 2018) old 7.18 (1877)	11.21 (July 2018) old 8.80 (2017)

Wettest Two-month or Seasonal periods

(Note: "Summer" =
June-July-August

"Fall" = Sep-Oct-Nov)

20.02 (Fall 2018)
old 19.56 (Fall 2006)

25.38 (Summer 1955)
25.34 (Summer 2018) 2nd

21.50 (Jun-Jul 2018)
old 17.20 (Jun-Jul 1889)

20.57 (Jul-Aug 2018)
old 18.65 (Jul-Aug 1955)

14.68 (Nov-Dec 2018)
old 13.00 (Nov-Dec 2009)

21.78 (Fall 1934)
20.36 (Fall 2018) 2nd

13.39(Nov-Dec 2018)
old 11.22 (Nov-Dec 2009)

22.61 (Summer 2018)
old 21.81 (Summer 1972)

18.88 (Fall 1979)
17.72 (Fall 2018) 2nd

18.44 (Jul-Aug 2018)
old 13.17(Jul-Aug 1984)

13.44 (Nov-Dec 2018)
old 13.15 (Nov-Dec 1972)

Other statistics

	BWI	DCA	IAD
Raindays	169 (1889) 145 (2018) 7th	159 (1889) 131 (2018) not signif.	155 (2003) 142 (2018) 4th
Days ½” or more	48 (2018) old 42 (1948)	44 (1937) 43 (2018) 2nd	48 (2018) old 42 (2003)
Days 1” or more	20 (2018) ties record from 1979	24 (2018) old 21 (1878)	23 (1996) 19 (2018) 3rd
Days 2” or more	6 (2018) ties record: 1952/1889	6 (1886 & 1878) 5 (2018) 3rd	5 (1993 & 1963) 4 (2018) 3rd
Consecutive Days		>1/4 inch: 7 days ending 5/19/2018 Old 5 days ending 9/9/2011	>1/4 inch: 7 days ending 5/19/2018 Old 5 days ending 9/9/2011

Specifically at BWI:

The wettest June, July, September, October, November, and December have all been since 2005.

The July total of 16.73 is the second wettest calendar month on record, behind 18.35 in August 1955.

Preliminary Precipitation Totals for 2018

Location	State	County	Total	Departure
MECHANICSVILLE 5 NE	MD	Saint Mary's	80.78	+35.03
MILLERS 4 NE	MD	Carroll	79.35	+34.71
FREE UNION	VA	Albemarle	78.62	+33.14
EMMITSBURG 2 SE	MD	Frederick	77.16	+33.45
FROSTBURG 2	MD	Allegany	74.58	+30.17
CHARLOTTESVILLE 2W	VA	Albemarle	72.14	+24.46
BAYARD	WV	Grant	71.86	+21.66
BWI AIRPORT	MD	Anne Arundel	71.82	+29.94
MOUNT WEATHER 3	VA	Clarke	71.08	N/A
CONOWINGO DAM	MD	Harford	70.25	+22.80
MARYLAND SCIENCE CENTER	MD	Baltimore	68.76	+27.87
NATIONAL ARBORETUM DC	DC	District of Columbia	68.01	+24.48
WILLIAMSPORT	MD	Washington	67.76	+27.17
KEYSER 2 SSW	WV	Mineral	67.22	+27.35
HAGERSTOWN 1 E	MD	Washington	67.10	N/A
CUMBERLAND 2	MD	Allegany	67.06	+29.70
WASHINGTON DULLES INTL AP	VA	Loudoun	66.74	+25.20
PURCELLVILLE	VA	Loudoun	66.55	N/A
WASHINGTON REAGAN NATIONAL AIRPORT	VA	Arlington	66.28	+26.54
BELTSVILLE	MD	Prince George's	65.90	+24.06
WINCHESTER	VA	Frederick	65.86	+27.53
OXON HILL	MD	Prince George's	65.26	+20.72
DAMASCUS 3 SSW	MD	Montgomery	65.01	+18.65
WFO STERLING	VA	Loudoun	64.66	+21.73
PATUXENT RIVER NAS	MD	Saint Mary's	63.66	+17.01
CHARLOTTESVILLE ALBEMARLE AP	VA	Albemarle	62.59	+19.88
STAUNTON WATER TREATMENT PLANT	VA	Augusta	58.85	+19.75
MILL GAP	VA	Highland	56.31	+12.03

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Autumn of 2017 and much of the winter of 2018 were quite dry in the mid-Atlantic region. Starting in April, greater and more routine rainfall began to occur, prompting several significant floods. We have done reviews of some of the events. Select the date (where available) for more information:

April 16th - Eastern West Virginia
May 15th & 16th - Frederick, Maryland
May 22nd - Fulks Run, Virginia
May 27th - Ellicott City & Catonsville, Maryland
May 30th & 31st - Charlottesville & Greene/Madison, Virginia
June 3rd - Berkeley Springs, West Virginia
June 22nd - Rappahannock River Basin, Virginia
July 21st - DC Metropolitan Area
July 24th - Northern Baltimore County
August 4th - North Central Maryland
August 13th - Baltimore Metropolitan Area
August 31st & September 1st - Harford County, Maryland & Northern Maryland
September 9th - Remnants of "Gordon"
September 17th & 18th - Remnants of "Florence"
November 24th & 25th - Thanksgiving weekend coastal low
December 15th & 16th - Coastal low with widespread flooding

Below are the monthly estimated rainfall totals for each month, starting in April. (Currently only April through June are available due to webpage issues. We intend to add the rest of the months soon.) Click on each image to make it larger: