Washington County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Washington County: 0.
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.

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.

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

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.

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.

Every earthquake of magnitude 4 or more within 50 miles

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 county boundary (or inside the county).
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.

Volcanoes within 100 miles

1. U.S. volcanoes within 100 miles, from the USGS Volcano Hazards Program. The threat category is the USGS 2018 National Volcanic Threat Assessment, which ranks volcanoes by how hazardous their past eruptions were and how many people and how much infrastructure lie near them. It is not a forecast of eruption.

USGS Volcano Hazards Program, retrieved October 30, 2026.

Mapped landslides

Mapped by OR DOGAMI (6,040), NASA (20).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Dec 7, 2015Flood$2.3 million
   National Weather Service narrative

   Heavy rain resulted in flooding of the Tualatin River near Dilly, and of many small creeks between Beaverton and Gaston. Around 50 homes sustained flood damage and many roads were closed including Highway 217 in Beaverton (during the evening commute).

2. Dec 3, 2007Flood$2.3 million
   National Weather Service narrative

   The Tualatin River near Dilley flooded, causing flood damage to homes in the area and leaving some roads impassable. Old Hwy. 47 and Hwy. 47 were closed temporarily due to combined flooding of a couple creeks with the Tualatin River. Near the area, a 54 year old male drown in Hedges Creek, a tributary of the Tualatin River. NOTE: Damage estimates are for the entire county of Washington.

3. Dec 9, 2015Flood$283,000
   National Weather Service narrative

   Heavy rain resulted in flooding of the Tualatin River near Dilley. High water flooded local businesses and residences.

4. Aug 5, 2003Lightning$150,000
   National Weather Service narrative

   Lightning struck a tree, and burning embers fell through an open window, starting a fire in both the interior and exterior of the home. Damage was estimated at $150,000.

5. Dec 18, 2015Flood$141,000
   National Weather Service narrative

   The Tualatin River flooded near Farmington and Dilley.

6. Jun 25, 2014Heavy Rain$140,000
   National Weather Service narrative

   Heavy rain from convective showers resulted in significant flooding near Beaverton. Flooding was reported of four homes, four apartments, several garages, the Winterhawks Skating Center, and a community pool. The city Public Works Director reported 2.3 inches of rain per hour, a personal weather station reported 2.29 inches of rain over 2 hours, and the National Weather Service Doppler radar estimated 1.7 inches per hour. A car stalled in a flooded high water in an underpass near the US 26-US 217 interchange. The cost damage is an estimate based on reports from the General Manager of the Skating Center and previous history of similar residential damage.

7. Oct 29, 2018Tornado$100,000
   National Weather Service narrative

   Multiple greenhouse structures were damaged at a farm on Thatcher Road. Witness accounts also confirmed a tornado. The tornado was likely on the ground for about 30 seconds to 1 minute.

8. Nov 20, 2024Heavy Rain$75,000
   National Weather Service narrative

   Oregon Department of Transportation reported in a KG8 media web article that heavy rain was the likely reason for the sinking and cracking of State Route 6 near the Gales Creek Campground Turnout. The westbound lane was closed November 20th and 21st.

9. Oct 31, 2015Heavy Rain$50,000
   National Weather Service narrative

   Heavy rain combined with clogged drains resulted in small stream and urban flooding. There were 16 instances where water or agricultural debris needed to be cleared from roadways. At least two residential basements were flooded in Beaverton. A large basement of an office building was flooded in Hillsboro.

10. Sep 15, 2013Lightning$28,000
    National Weather Service narrative

    A tree hit by lightning fell and damaged two homes in Aloha.

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

116°FJun 28, 2021

All-time low

−3°FFeb 2, 1950

Warmest night

75°FJun 28, 2021

Coldest day

14°FDec 30, 1968

Wettest day

2.69 inNov 19, 1996

Snowiest day

14.4 inJan 21, 1943

Hottest year

2015mean 57.4°F

Coldest year

1964mean 50.1°F

Wettest year

199663.20 in

Driest year

198522.48 in

Snowiest season

44.5 in1949-50

Station Portland International Airport (USW00024229), 22 ft elevation, 14.8 miles from the population centre. Daily records from 1938 to October 26, 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.

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.

Neighbouring counties

• 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 USW00024229.
• 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.
• Volcanoes USGS Volcano Hazards Program, U.S. volcanoes and 2018 threat assessment.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• 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.