Herndon

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 Fairfax County, the county that contains Herndon.

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 Fairfax County, the county that contains Herndon.

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 Fairfax County, the county that contains Herndon.

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. Sep 18, 2003Tropical Storm, Fairfax$18.0 million
   National Weather Service narrative

   On September 18, 2003, Hurricane Isabel made landfall on the North Carolina Coast. Its huge wind field was already piling water up into the southern Chesapeake Bay. By the time Isabel moved into central Virginia, it had weakened and was downgraded to a tropical storm. Isabel's eye tracked well west of the bay, but the storm's 40 to 60 mph sustained winds pushed a bulge of water northward up the bay and its tributaries producing a record storm surge. The Virginia western shore counties of the Chesapeake Bay and the tidal tributaries of the Potomac, Rappahannock and other smaller rivers, experienced a storm surge which reached 5 to 9 feet above normal tides. In many locations,…

2. Jun 25, 2006Flash Flood$11.0 million
   National Weather Service narrative

   Flash flooding occurred when Cameron Run came out of its banks. 158 homes were declared uninhabitable by building inspectors due to contamination and/or lack of utilities. Another two homes and one business were condemned. Estimated damage $11 million.

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

   NWS Storm Survey indicated a wet microburst produced near 70 mph winds. A dozen homes were damaged near Woodland Road in Annandale. According to newspaper accounts, three of the homes were evacuated due to structural damages and gas leaks. The extensive tree damage was likely exacerbated by weakened tree roots from the significant rains that occurred just a week earlier in late June.

4. Jun 24, 1996Tornado$4.0 million
   National Weather Service narrative

   A tornado, associated with the mesocyclone of a heavy-precipitation supercell, touched down in extreme southeastern Loudoun Co near the Bull Run, then proceeded east-southeast for 20 miles, knocking down over 1000 trees and causing substantial property damage, especially in western Fairfax County, before lifting along the Capital Beltway at the Braddock Road interchange less than 2 miles west of Annandale.While moving over rural terrain in extreme southeastern Loudoun and extreme western Fairfax Cos, the tornado uprooted or snapped tens of trees. The storm rapidly intensified over western Fairfax Co, where it produced F2 damage. The storm uprooted or snapped hundreds of trees…

5. Apr 23, 1999Hail$3.0 million
   National Weather Service narrative

   A line of thunderstorms developed in West Virginia during the early afternoon and moved rapidly southeast across Northern Virginia. These storms produced very large hail in a 10 mile wide strip from Winchester in Frederick County to Woodbridge in Prince William County from 3:30 PM EDT to 5:00 PM EDT. Winds over 55 MPH also downed trees and power lines in Frederick and Clarke County between 3:30 PM EDT and 4:15 PM EDT. Frederick County spotters reported between 1 3/4 to 3 1/2 inch diameter hail. The rubber membrane roof of the War Memorial Building in Winchester was punctured by hail the size of golf balls, allowing heavy rain to fall inside the structure and cause significant…

6. Apr 23, 1999Hail$3.0 million
   National Weather Service narrative

   A line of thunderstorms developed in West Virginia during the early afternoon and moved rapidly southeast across Northern Virginia. These storms produced very large hail in a 10 mile wide strip from Winchester in Frederick County to Woodbridge in Prince William County from 3:30 PM EDT to 5:00 PM EDT. Winds over 55 MPH also downed trees and power lines in Frederick and Clarke County between 3:30 PM EDT and 4:15 PM EDT. Frederick County spotters reported between 1 3/4 to 3 1/2 inch diameter hail. The rubber membrane roof of the War Memorial Building in Winchester was punctured by hail the size of golf balls, allowing heavy rain to fall inside the structure and cause significant…

7. Sep 17, 2004Tornado$2.5 million
   National Weather Service narrative

   A tornadic thunderstorm entered western Fairfax County from Prince William County. The storm had a path of about 7 miles. Beginning on Old Centerville Road, the storm produced scattered tree damage along its path and minor roofing damage to structures in the London Town Area. A line of damage was carved from Lee Highway northward into the Centerville and Chantilly areas.The tornado destroyed one estate and damaged about 50 other dwellings. The storm was also responsible for downed trees and power lines. The tornado lifted as it crossed Route 50.

8. Apr 23, 1999Hail$2.0 million
   National Weather Service narrative

   A line of thunderstorms developed in West Virginia during the early afternoon and moved rapidly southeast across Northern Virginia. These storms produced very large hail in a 10 mile wide strip from Winchester in Frederick County to Woodbridge in Prince William County from 3:30 PM EDT to 5:00 PM EDT. Winds over 55 MPH also downed trees and power lines in Frederick and Clarke County between 3:30 PM EDT and 4:15 PM EDT. Frederick County spotters reported between 1 3/4 to 3 1/2 inch diameter hail. The rubber membrane roof of the War Memorial Building in Winchester was punctured by hail the size of golf balls, allowing heavy rain to fall inside the structure and cause significant…

9. Jan 19, 1996Flood, Fairfax$2.0 million
   National Weather Service narrative

   ***River Flooding***High dewpoint temperatures melted most of the snow on the ground within 12 hours. The snow pack had a liquid equivalent between 2 to 3 inches. Snowmelt, combined with 1 to 3 inches of rain (some locations received nearly 5 inches), caused the worst regional flooding in over 10 years. River flooding began during the flood/flash flood event along the headwaters of all basins and continued downstream through the 22nd. Crests ranged from 3 to 21 feet above flood stage.High water caused millions of dollars in damage, closed roads, destroyed homes and businesses, and forced the evacuation of several towns. Four people were rescued by the National Park Service and…

10. Apr 23, 1999Hail$2.0 million
    National Weather Service narrative

    A line of thunderstorms developed in West Virginia during the early afternoon and moved rapidly southeast across Northern Virginia. These storms produced very large hail in a 10 mile wide strip from Winchester in Frederick County to Woodbridge in Prince William County from 3:30 PM EDT to 5:00 PM EDT. Winds over 55 MPH also downed trees and power lines in Frederick and Clarke County between 3:30 PM EDT and 4:15 PM EDT. Frederick County spotters reported between 1 3/4 to 3 1/2 inch diameter hail. The rubber membrane roof of the War Memorial Building in Winchester was punctured by hail the size of golf balls, allowing heavy rain to fall inside the structure and cause significant…

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, 4.1 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 Fairfax 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.