Summit County, Utah

What hazards hit Summit County most?

The most frequent records are winter storm records: 778 since 1996. 41% of its winter storm records since 1996 fell in December and January. The rank column places the county among Utah's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

When was the last damaging storm in Summit County?

The most recent record with damage, injuries or deaths is the February 22, 2026 avalanche (1 death and 1 injury).

A group of seven snowbikers met in Big Cottonwood Canyon and the Guardsmans Pass trailhead with the intention to ride in the area during the afternoon. Most of the group had extensive backcountry, including formal avalanche training, and members of the group were equipped with transceiver (though no transceiver check was performed), probe, shovel, and avalanche airbag. While they were aware of the conditions, including considerable avalanche danger rating (per Utah Avalanche Center), they set out planning to stick to low-angle slopes in Caribou Basin which they knew well. While riding, they observed numerous avalanches, and noted the loose underlying snow characteristics when getting one member unstuck from deep snow. After taking a break, the group decided to do one more session around the basin before returning to the trailhead. …
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1306850)

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Summit County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Landslides and avalanches in the 2020-26: 21 records against 7 in the decade before, 21 of them forecast-zone records. Cells marked z rose mostly through zone records. The local National Weather Service office files these once per forecast zone, so a change in how it draws its zones or splits a storm into records moves this count as much as the weather does; read it beside the Summit County days with a record above.

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

41% of its winter storm records since 1996 fell in December and January. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Summit County

FEMA's register lists 10 declarations that include Summit County: 4 major disasters, 3 emergencies and 3 fire management assistance declarations. Most were for fire (3) and flood (3).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Summit County had?

NOAA's Storm Events Database holds 9 flood or flash flood records for Summit County from 1997 to 2022, on 9 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Summit County ranks 1694th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $153,000 on 46 claims filed in Summit County; the most in one year was 8 in 2023. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Summit County

FEMA's National Risk Index rates Summit County Relatively Low overall, with an expected annual loss of $38.6 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Summit County

1. Salt Lake County 1,445
2. Wasatch County 1,211
3. Summit County 985
4. Sweetwater County, WY 864
5. Morgan County 708
6. Daggett County 587
7. Duchesne County 544
8. Rich County 476
9. Uinta County, WY 162

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Winter storms in UtahThe state's winter storm records, by county, year and month
• The Utah recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Summit CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Summit County's FEMA declarations (CSV)10 rows: every declaration that named the county, for your own analysis