Teton County

Every recorded tornado

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

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 ID GS (30).

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. Jan 7, 2022Winter Storm, Centennial Mountains-Island Park$100,000
   National Weather Service narrative

   Whiteout conditions caused by 40 plus mph wind gusts created a 40 vehicle crash on US Highway 20 in the east bound lane on January 7th. It initially occurred when a semi crashed into a stopped vehicle that was stopped due to the low visibility. Ambulances were involved in the pile up. The location was in the Henry's Lake flats in between Idaho Highway 87 and Island Park. Two police deputies were struck as well. Only very minor injuries were reported in the pile up with no deaths. The crash occurred at around 3 pm MST and US Highway 20 was closed for several hours as well as Idaho Highway 87 from Island Park to the Montana state line for several hours. Both were re-opened on the…

2. Feb 6, 2017Flood$90,000
   National Weather Service narrative

   Some minor sheet flooding occurred at low elevations along with some road damage aided in part by the cold and snowy winter after the warmup in February.

3. Nov 27, 2022Winter Storm, Centennial Mountains-Island Park$25,000
   National Weather Service narrative

   Snow combined with wind gusts over 40 mph caused US Highway 20 to close on the 27th from Ashton to Targhee Pass as well as Idaho Highway 87 between US Highway 20 and Raynolds Pass. Many automobile accidents and slide offs were reported on US 20. Seven to 8 crashes were reported on US 20. Both highways closed at around 5 PM MST on the 27th. Snow amounts were in the 3 to 6 inch range in Island Park with 10 inches estimated at the White Elephant SNOTEL site. Wind gusts were widespread in the 35 to 45 mph range. Roads were reopened at 3 AM MST Monday the 28th.

4. Jul 18, 1999Lightning$21,000
   National Weather Service narrative

   Lightning struck a lone tree, killing all 15 head of cattle which had gathered about it.

5. Dec 23, 2023Winter Weather, Centennial Mountains-Island Park$20,000
   National Weather Service narrative

   Two to 4 inches of snow fell and combined with strong winds to create hazardous travel. Rocky Mountain Power reported 400 customers without power by 530 AM due to the winds and snow in the Ashton area and north. A jackknifed semi trailer occurred on US Highway 20 just north of Idaho Highway 87 blocking the road at 909 AM. Fremont County reported numerous crashes and slide offs in the Island Park area.

6. Oct 13, 2013Lightning$20,000
   National Weather Service narrative

   Lightning struck a tree that was connected to a barbed wire fence on a ranch in Tetonia. The current from the fence killed 15 cattle lined up next to the fence. Cost to the rancher was between 15 and 20 thousand dollars.

7. May 1, 2017Flood$17,000
   National Weather Service narrative

   Minor flooding occurred in May with snow melt being the main contributor to the flooding. Field flooding caused agricultural damage and many roads and recreational facilities received damage.

8. Apr 12, 2023Winter Weather, Teton Valley$15,000
   National Weather Service narrative

   A winter and spring of heavy snow led to snow weight collapsing 3 structures including a garage near Ashton, a farm shed near Ashton and a canopy covering a fuel filling station at Mack's Inn in Island Park. Damages were 30,000 dollars.

9. Apr 12, 2023Winter Weather, Centennial Mountains-Island Park$15,000
   National Weather Service narrative

   A winter and spring of heavy snow led to snow weight collapsing 3 structures including a garage near Ashton, a farm shed near Ashton and a canopy covering a fuel filling station at Mack's Inn in Island Park. Damages were 30,000 dollars.

10. Mar 1, 2024Winter Storm, Teton Valley$15,000
    National Weather Service narrative

    Heavy snow fell and combined with strong winds to bring extensive travel problems with periods of road closures for 4 days. 15 inches of snow was measured in Driggs. Idaho Highway 32 was closed from Ashton to Tetonia on the 1st and 2nd. Idaho Highway 33 was closed on the 2nd from Newdale to Tetonia. Driggs and the Teton Valley had extensive power outages on the 2nd. US Highway 20 was closed from Ashton to the Montana border on the 2nd. Idaho Highway 32 closed from Ashton to Tetonia was closed on the 4th. Idaho Highway 47 was closed from Ashton to Bear Gulch on the 4th. Idaho Highway 33 was closed from Newdale to Tetonia on the 4th. The closure caused by a 15 vehicle pileup in the…

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

98°FJul 12, 2026

All-time low

−46°FFeb 9, 1933

Warmest night

65°F4 times, most recently Jul 21, 2026

Coldest day

−10°FDec 23, 1983

Wettest day

2.70 inNov 11, 1912

Snowiest day

31.0 inDec 30, 1923

Hottest year

1934mean 44.3°F

Coldest year

1912mean 35.2°F

Wettest year

198333.62 in

Driest year

193310.47 in

Snowiest season

187.0 in2010-11

Station Alta 1 Nnw (USC00480140), 6,440 ft elevation, 7.1 miles from the population centre. Daily records from 1909 to September 30, 2026; 98.5% 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 USC00480140.
• 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.