Union County

Every recorded tornado

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

Every large fire

1. Large fires mapped by the Monitoring Trends in Burn Severity program since 1984: 1,000 acres or more in the West, 500 or more in the East. Prescribed burns are excluded. Acres here are the part of each perimeter inside this place.

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service), 1984 to 2026.

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.

Mapped landslides

Mapped by OR DOGAMI (498), NASA (3).

Deadly landslides

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. May 15, 2011Flood$2.0 million
   National Weather Service narrative

   Heavy rainfall on above average snow pack produced record flood stage of 7.7 feet on the Grande Ronde River at Perry. Additional flooding occurred on Little Creek, Wolf Creek, Ladd Creek, and Catherine Creek. Flooding impacted 12 thousand acres of crops and dozens of homes and businesses. Twenty-county roads and state roads were covered including Highway 204 west of LaGrande. Flooding also occurred at Hilgard and Red Bridge State Parks west of LaGrande.

2. Feb 6, 2020Flood$750,000
   National Weather Service narrative

   There was moderate flooding along the Grande Ronde River from near Hilgard Junction through La Grande and Island City and Imbler to Elgin. In addition, the rapid snowmelt and heavy rain cause widespread flooding along a number of small streams and creeks with water over roads and filling fields. Highways 237 and 244 were closed due to flooding and plugged culverts due to rock slides. Damage was estimated at 750,777 dollars. Grande Ronde near Perry - Flood stage is 6.6 feet. The river rose above flood stage on February 6th at 245 pm, crested at 8.54 feet on Feb 7th at 1 am, then fell below flood stage on February 8 at 1245 am. There was moderate flooding along the Grande Ronde…

3. Nov 12, 2007High Wind, Wallowa County$500,000
   National Weather Service narrative

   A deep low pressure area moving across British Columbia combined with very strong upper level winds produced damaging surface winds across northeast Oregon. The winds were most devastating near Wallowa Lake where dozens of trees were downed and crashed into buildings and vehicles. Wallowa Lake State Park was closed as a result of the damage. Wind gusts in miles per hour across the area include Pendleton (62), Pilot Rock (60), Joseph (78), 10 miles south of Imnaha (61), Long Creek (64), 3 miles north of Helix (59). Sustained winds over 40 mph were measured at Hot Lake and North Powder. A wind gust to 111 mph was measured at Sheep Ridge, near Enterprise at an elevation of 7000 feet.

4. Jul 19, 2004Thunderstorm Wind$300,000
   National Weather Service narrative

   A severe thunderstorm produced wind gusts estimated at 80 MPH...which led to several damage reports and one injury. A modular building was flipped and rolled over four times at a distance of 120 feet, before coming to a stop when hitting a cessna aircraft at the La Grande Airport. One person was inside the building at the time, and was hospitalized and later released. The aircraft sustained a broken windshield, crumpled nose, and smashed nose wheel. Four additional planes were damaged during the storm. A satellite dish and a computer were destroyed at the airport as well. Numerous trees and power lines downed throughout La Grande and Island City. The hardest hit areas in Island…

5. Apr 8, 2019Flood$250,000
   National Weather Service narrative

   There was widespread flooding of fields and lowlands along the river across Union County. There were at least 5000 acres of agricultural land flooded and numerous roads had damage.

6. Jul 7, 2012Thunderstorm Wind$100,000
   National Weather Service narrative

   Witnesses described a sudden microburst damaged two locations west of Summerville. A large tree crashed through one house, while the residents were not at home. Another downed tree took out a power line and damaged the roof.

7. Nov 12, 2006High Wind, Wallowa County$50,000
   National Weather Service narrative

   A strong low pressure system moving across northern Washington brought high winds and damage.

8. Nov 28, 2001Blizzard, Wallowa County$50,000
   National Weather Service narrative

   A blizzard struck Wallowa County during the morning. A wind gust of 64 mph was recorded at 10:30 am 3 miles north of Joseph. 20 large trees were downed a Wallowa Lake State Park, which is 7 mile north of Joseph. One tree fell across a summer cabin, causing extensive damage. Power was lost to the state park for 10 hours as power lines were cut by falling trees in several places. Law enforcement reported blizzard conditions along highway 82 between Minam and Joseph. During the late morning and early afternoon, visibilities were reduced to 500 feet as 3 to 8 inches of snow fell along this route. Over higher terrain in the northern part of the county, snow amounts were higher. One…

9. Feb 27, 2012Freezing Fog, Northern Blue Mountains$50,000
   National Weather Service narrative

   Dense freezing fog and icy roads with a dusting of snow caused a 12 vehicle crash with minor injuries on I-84 near Deadman's Pass. Visibility was reduced to 100 feet or less in spots.

10. Aug 13, 1999Lightning$46,000
    National Weather Service narrative

    Early morning thunderstorms in the Grande Ronde valley produced frequent lightning and small hail. 800 customers in the towns of Elgin, Summerville and Imbler lost power for several hours. Two costly fires were started by lightning...one of which was a house fire which damaged a home in Imbler. The second fire started in a haystack and caused 46 thousand dollars worth of damage.

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

108°F3 times, most recently Jul 1, 2021

All-time low

−18°FDec 23, 1983

Warmest night

75°FJul 31, 2000

Coldest day

−2°FDec 24, 1990

Wettest day

2.70 inNov 26, 1999

Snowiest day

20.0 inJan 23, 1982

Hottest year

2025mean 52.1°F

Coldest year

1985mean 44.7°F

Wettest year

199524.43 in

Driest year

200210.51 in

Snowiest season

61.5 in1971-72

Station La Grande (USC00354622), 2,755 ft elevation, 3.2 miles from the population centre. Daily records from 1965 to October 22, 2026; 93.2% 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 USC00354622.
• 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.
• 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.