Flash Flood in Connecticut
Every flash flood event the National Weather Service has filed in Connecticut, year by year, with the most significant episodes. Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
The most significant on the map
The most significant flash flood episodes in Connecticut.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The record
- Events
- 619
- Deaths
- 5
- Injuries
- 0
- Damage
- $24 million
Every year
The most significant
Ranked by deaths, injuries, damage and size together.
- Flash Flooding in Connecticut, August 18, 2024A frontal system over the area on August 18th allowed for the development of rain early in the morning.
- Flash Flooding and Flooding in Connecticut, October 1, 2010Low pressure tracked up the east coast and interacted with a stalled frontal boundary and approaching upper level low pressure system.
- Flash Flooding and Heavy Rain in Connecticut, September 16 to 18, 1999Torrential record rainfall, which caused serious widespread urban, small stream, and river flooding, preceded the remnants of Hurricane Floyd, which passed over Western Suffolk County of Long Island around 8 pm and across Central Connecticut from 9 pm to 11 pm on the 16th.Death:…
- Flash Flooding and Flood in Connecticut, September 6 to 7, 2008Tropical Storm Hanna impacted Southern Connecticut, making landfall near the Nassau/Suffolk County border in New York around 10:35 pm on the 6th. Storm total rainfall ranged from 2.76 inches at Groton Airport to 6.45 inches at New Canaan.
- Flash Flooding and Flood in Connecticut, September 2, 2021The remnants of Tropical Cyclone Ida resulted in several reports of flash flooding over during the early morning hours of September 2. Rainfall from the evening of the 1st through the early morning hours of the 2nd totaled three to six inches.
- Flash Flooding and Flooding in Connecticut, September 1 to 2, 2021Extremely heavy rainfall associated with the remnants of Hurricane Ida overspread southern Connecticut during the evening of September 1 and continued through the early morning hours of September 2.
- Flash Flooding in Connecticut, August 11 to 12, 2000A series of thunderstorms developed and dissipated as they moved very slowly over an area covering East Bridgeport and Stratford. Torrential rain caused widespread serious flash flooding of low lying areas, poor drainage areas, and small streams.
- Flash Flooding and Flooding in Connecticut, July 9 to 10, 2023A strong upper-level system brought widespread rounds of showers and thunderstorms to northwestern Connecticut on July 9-10, 2023. Northern and western portions of the county were hardest hit with rainfall amounts between 4 and 7 inches.
- Flash Flood in Connecticut, October 11, 2007A low pressure system slowly moved north from the Mid-Atlantic coast across New England and produced flash flooding across portions of Connecticut.
- Flash Flood in Connecticut, April 16, 1996As a low pressure system over the midwest on Monday April 15th, moved northeast, its' associated warm and cold fronts moved across the area during the evening of Tuesday, April 16th.With abundant moisture and unstable air in place, heavy rain and southeast winds gusting over 34…
- Flash Flooding in Connecticut, July 8, 2011The combination of an approaching upper level disturbance and a stationary front in the vicinity produced thunderstorms with very heavy rainfall that caused flash flooding in Middlesex and New Haven Counties.
- Flash Flood and High Wind in Connecticut, September 16 to 17, 1999The remnants of Hurricane Floyd moved up the eastern seaboard on September 16 and during the early hours on September 17. The storm brought both high winds and exceptionally heavy rainfall to northwestern Connecticut, which included a large swath of 5 to 8 inch amounts.
- Tropical Storm and Flash Flooding in Connecticut, August 22, 2021Tropical Storm Henri made landfall in southwest Rhode Island around noon on August 22nd, then moved slowly northwestward and westward across northern Connecticut and weakened. Henri brought strong wind gusts and flash flooding.
- Flash Flood in Connecticut, May 27, 2008Strong thunderstorms in advance of a cold front crossed the tri-state area on May 27th producing isolated flash flooding in New Haven County.
- Flash Flood and Heavy Rain in Connecticut, August 29, 1997A cold front moving very slowly across Connecticut caused an area of showers and thunderstorms that produced intense rainfall amounts of 3 to 6 inches in 1 to 3 hours across parts of Hartford County.
- Flash Flooding in Connecticut, September 2, 2021On Sept. 1, Tropical Depression Ida tracked northeasward from the central Appalachians and arrived in southern New England late in the day as a remnant low.
- Flash Flood and Damaging Winds in Connecticut, August 12, 2016A mid level disturbance and an approaching cold front resulted in showers and thunderstorms developing over much of southern New England. Like the storms the previous day, frequent lightning accompanied these storms. In addition, wind damage and flooding occurred.
- Tornado and Flash Flood in Connecticut, July 10, 2013A warm front lifted northward through Southern New England, igniting showers and thunderstorms across much of the area.
- Tornado and Flash Flooding in Connecticut, August 19, 2021The remnants of Tropical Storm Fred moved across Southern New England producing heavy rain, gusty winds, and two tornadoes - one that moved from northeast Connecticut into Worcester County and another in central Worcester County.
- Flash Flooding and High Wind in Connecticut, December 17, 2000A complex storm system began to evolve on Saturday December 16 across the Mississippi Valley. A surface low tracked north into the eastern Great Lakes by December 17.
- Flash Flood and Damaging Winds in Connecticut, July 27, 2005A hot and humid airmass combined with an approaching cold front sparked strong to severe thunderstorms across southern New Hampshire during the late afternoon and early evening hours of 27 July.
- Flash Flooding in Connecticut, June 17, 2001The remnants of tropical storm Allison joined forces with a slow moving cold front from the west, to produce torrential rainfall over much of Litchfield County on June 17.
- Flash Flooding and Flood in Connecticut, September 8, 2011A slow moving cold front moved across Southern New England and stalled just south of the area. This front was instrumental in bringing tropical moisture from the remnants of Tropical Storm Lee into New England.
- Flash Flooding in Connecticut, September 13, 2023A cluster of heavy rain producing thunderstorms along and near a surface low and cold frontal boundary resulted in numerous road closures and roads being washed out on September 13, 2023. Flooding was mostly concentrated within the towns of Washington and Roxbury.
- Tornado and Flash Flooding in Connecticut, July 17 to 18, 2021A relatively stationary front meandered across southern New England on the 17th and 18th while low pressure slowly moved along the front. At upper levels, an upper low was moving slowly eastward from the Great Lakes.
More
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.