Rockville

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond this area.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Flood insurance figures are for Montgomery County, the county that contains Rockville.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges in Montgomery County, the county that contains Rockville.

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

The drought index is for Montgomery County, the county that contains Rockville.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the city centre.
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

More event types since 1996

Costliest events since 1996

1. Jan 19, 1996Flood, Montgomery$20.0 million
   National Weather Service narrative

   *** River Flooding ***High dew point temperatures melted most of the snow on the ground within 12 hours, with liquid water equivalent ranging from 1 to 3 inches. Snowmelt combined with 1 to 3 inches of rain (some locations received 5 inches) to produce, in some cases, catastrophic river flooding. The flooding was the worst in the region since 1985. River flooding began during the flood/flash flood event along the headwaters of the basins and continued downstream through the 22nd. Crests ranged from 3 to 21 feet above flood stage. Record flooding occurred on Wills Creek near Cumberland (MDZ002), damaging all dwellings in the town of Locust Grove. Almost all dwellings in the town of…

2. Jul 29, 2023Thunderstorm Wind$10.0 million
   National Weather Service narrative

   Hundreds of trees, branches and wires blew down between Rockville and North Bethesda. Trees blew down onto cars and porches in the Bethesda Park Condo Complex, displacing residents. The roof blew off of The Original Pancake House in the 12200 block of MD-355 Rockville Pike; the roof partially blew off another building across the street. Large trees blew down onto structures in the 1200 block of Charles Road. Trees blew down on southbound MD-185 Connecticut Avenue at MD-586 Veirs Mill Road. Numeorus trees blew down along Tilden Lane. Trees blew down on MD-355 Rockville Pike at I-495 Capital Beltway. A large tree blew down onto two residences on Charles Road trapping several people.

3. Jun 5, 2024Tornado$5.0 million
   National Weather Service narrative

   The tornado began just east of the Seneca Creek State Park. Staff at the Washington Suburban Sanitary Commissions (WSSC) Seneca Water Resource Recovery Facility witnessed the tornado moving west-to-east directly adjacent to the south of their facility where power lines leading to the facility were snapped causing the facility to|switch to backup power. After its trek south of the facility, it produced large broken branches that fell onto Great Seneca Highway (MD-119), partially blocking the roadway.||The storm continued east and entered the City of Gaithersburg. The first damage surveyed was along Desellum Avenue north of Gaithersburg High School. Here, pine trees were snapped,…

4. Jul 2, 2006Thunderstorm Wind$5.0 million
   National Weather Service narrative

   Extensive tree and powerline damage occurred from Silver Spring to Wheaton, Aspen Hill, and White Oak. Several homes were struck by trees which caused extensive property damage in the neighborhoods. PEPCO reported more than 18,000 customers without power in Montgomery County.

5. Oct 29, 2012High Wind, Montgomery$3.7 million
   National Weather Service narrative

   Wind gusts of 58-70 mph were measured by spotters and a mesonet. There were scattered trees and power lines down throughout the county.

6. Jan 14, 1999Ice Storm, Montgomery$2.9 million
   National Weather Service narrative

   A strong arctic cold front moved slowly southeast across the Mid-Atlantic region from late on the 13th to midday on the 15th. This front brought a thick layer of sub freezing air to the lowest levels of the atmosphere, but just off the surface warmer air moved in. A low pressure system developed on the 13th over the Tennessee Valley. The low moved into the Mid Atlantic region over the next few days, spreading precipitation region wide from early on the 13th through midday on the 15th. The precipitation started as snow but melted into rain as it fell through the warm layer of air. Unfortunately west of the cold front the ground was below freezing during the period so the rain froze…

7. Aug 10, 2021Lightning$2.5 million
   National Weather Service narrative

   Lightning struck a 3-story apartment building in the 13100 block of Millhaven Place. The lightning strike started a severe fire that started in the attic and caused the building to collapse, displacing a dozen families and causing an estimated 2.5 million dollars in damage.

8. Jul 29, 2023Thunderstorm Wind$2.0 million
   National Weather Service narrative

   Dozens of trees, branches and wires blew down near Glen Echo and Cabin John. Numerous trees blew down onto power lines. Cabin John Parkway, Clara Barton Parkway, and Macarthur Boulevard remained closed for several days due to downed trees. A tree blew down onto a house in the 6000 block of Cromwell Drive. Trees blew down on eastbound MD-190 River Road at Whittier Boulevard. Trees blew down on eastbound MD-614 Goldsboro Road at Wedgewood Road.

9. Jun 20, 2001Lightning$2.0 million
   National Weather Service narrative

   Eighty people were displaced after a lightning fire severely damaged an apartment complex. The event time was estimated.

10. Jun 25, 2006Flash Flood$1.6 million
    National Weather Service narrative

    Numerous county roads closed in the southeastern part of the county near the Washington DC line. There were 147 reports of flooded basements. Twenty five swift water rescues occurred. In Chevy Chase, firefighters used boats to rescue 30 people trapped inside a recreational center. The Chevy Chase Village area off Wisconsin Ave had knee-deep water. There were 45 individual rescues Meadowbrook Park. Water reached the window of a stalled car on a bridge over great Seneca Creek in upper Montgomery County. A road was washed out at US 29 at New Hampshire Avenue in Silver Spring. Three swift water rescues occurred in Rock Creek Park. About 26 vehicles were recovered after water reached…

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

105°FJul 22, 2011

All-time low

−18°FJan 22, 1984

Warmest night

81°FJul 16, 2026

Coldest day

6°FJan 19, 1994

Wettest day

10.67 inJun 21, 1972

Snowiest day

22.5 inFeb 11, 1983

Hottest year

2024mean 58.9°F

Coldest year

1976mean 51.9°F

Wettest year

201866.74 in

Driest year

200727.02 in

Snowiest season

73.2 in2009-10

Station Washington Dulles International Airport (USW00093738), 294 ft elevation, 18.7 miles from the city centre. Daily records from 1960 to October 27, 2026; 100.0% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

Declarations for Montgomery County.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USW00093738.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.