Original analysis of NOAA, FEMA and Census data
Salt Lake City freeze and flood data
Salt Lake City International Airport now sees about 16.4 nights a year at 20°F or colder, half the 32.1 it averaged over 1991-2020. The air stays dry most of the year, and flood insurance claims are rare. Here is the record by year, month and ZIP code, and what it means for water damage in the valley.
Nights per year at 20°F or colder, Salt Lake City airport
Average nights at or below freezing, by month
What we found
- Hard freezes fell by half. 32.1 nights a year at or below 20°F over 1991-2020, 16.4 over 2016-2025. In the 1970s it was 39.7. Nights at 10°F or colder dropped from 6.4 to 1.6 a year.
- But the cold snaps still come. 2013 had 56 nights at 20°F or colder. The longest run of days that never got above freezing was 24 days, January 3, 2004 to January 26, 2004. The record low is -30°F on February 9, 1933.
- Freezing season runs late October to early April. The average first fall freeze over 2016-2025 came around October 28 and the last spring freeze around April 4. December and January carry most of the hard freezes.
- The air is dry, especially in summer. Outdoor relative humidity averages 26% in July and 74% in January. About 149 days a year average below 40%. That helps surface drying, and does nothing for water trapped under a floor.
- Rain comes in bursts. The airport averaged 14.8 inches of precipitation a year over 2016-2025. October 4, 2025 brought 2.47 inches, the wettest day in the airport record back to 1928. The National Weather Service called it the second wettest day in Salt Lake City records, behind 2.64 inches downtown in 1901 (Deseret News).
- Flood claims are rare and old. 591 NFIP claims in Salt Lake and Davis counties, 314 of them from 1982 to 1984, $2.8 million paid in all. Since 2015 there have been 88.
Average outdoor relative humidity by month (%)
Average precipitation by month (inches, rain plus melted snow)
Coldest nights on record
| Date | Low |
|---|---|
| February 9, 1933 | -30°F |
| January 25, 1949 | -22°F |
| December 13, 1932 | -21°F |
| January 21, 1937 | -20°F |
| January 21, 1930 | -18°F |
| January 12, 1963 | -18°F |
Longest stretches below freezing all day
| Dates | Length |
|---|---|
| January 3, 2004 to January 26, 2004 | 24 days |
| January 23, 1949 to February 9, 1949 | 18 days |
| December 20, 1990 to January 6, 1991 | 18 days |
| January 12, 2007 to January 29, 2007 | 18 days |
| January 21, 1962 to February 6, 1962 | 17 days |
Wettest days on record
| Date | Precipitation |
|---|---|
| October 4, 2025 | 2.47 in |
| July 13, 1962 | 2.28 in |
| September 26, 1982 | 2.27 in |
| September 5, 1970 | 2.19 in |
| March 23, 2017 | 1.97 in |
| August 26, 1932 | 1.96 in |
NOAA ACIS, Salt Lake City International Airport, 1928 to October 28, 2026.
Flood insurance claims per year, Salt Lake and Davis counties
Housing and flood claims by ZIP code
Older housing stock is the best single guide to old supply lines, clay sewer laterals and unfinished-then-finished basements. Flood claims mark the few places near the Jordan River and its creeks where outside water has gotten in.
| ZIP | Area | Median year built | Built before 1980 | Renter occupied | Homes | NFIP claims | Since 2015 |
|---|---|---|---|---|---|---|---|
| 84010 | Bountiful | 1973 | 44% | 30% | 16,489 | 40 | 7 |
| 84020 | Draper | 2003 | 3% | 31% | 17,448 | 12 | 7 |
| 84044 | Magna | 1985 | 25% | 21% | 9,319 | 6 | 1 |
| 84047 | Midvale | 1987 | 24% | 56% | 17,036 | 0 | 0 |
| 84054 | North Salt Lake | 2002 | 10% | 33% | 7,798 | 3 | 0 |
| 84065 | Riverton | 2002 | 6% | 16% | 16,169 | 13 | 4 |
| 84070 | Sandy (west) | 1992 | 19% | 43% | 12,256 | 1 | 0 |
| 84084 | West Jordan | 1985 | 8% | 27% | 10,610 | 0 | 0 |
| 84088 | West Jordan (south) | 1993 | 5% | 25% | 13,519 | 4 | 0 |
| 84092 | Sandy (east) | 1984 | 4% | 10% | 9,919 | 4 | 1 |
| 84093 | Sandy (Granite) | 1978 | 12% | 7% | 8,166 | 7 | 2 |
| 84094 | Sandy (central) | 1980 | 20% | 24% | 9,883 | 1 | 0 |
| 84095 | South Jordan | 2003 | 6% | 25% | 13,654 | 8 | 2 |
| 84101 | Downtown | 2006 | 19% | 79% | 6,497 | 10 | 0 |
| 84102 | Central City and East Central | 1961 | 61% | 76% | 11,505 | 1 | 0 |
| 84103 | The Avenues and Capitol Hill | 1962 | 58% | 59% | 13,872 | 1 | 0 |
| 84104 | Glendale and Poplar Grove | 1962 | 57% | 38% | 8,636 | 27 | 0 |
| 84105 | Sugar House (east) and Yalecrest | 1938 | 82% | 41% | 11,254 | 21 | 4 |
| 84106 | Sugar House and Millcreek | 1965 | 55% | 39% | 17,306 | 23 | 6 |
| 84107 | Murray | 1979 | 29% | 55% | 17,676 | 95 | 2 |
| 84108 | East Bench and Foothill | 1958 | 68% | 25% | 8,360 | 11 | 4 |
| 84109 | East Millcreek and Olympus Cove | 1960 | 69% | 20% | 9,909 | 4 | 3 |
| 84111 | Downtown (east) and Central City | 1987 | 36% | 78% | 8,956 | 13 | 0 |
| 84115 | South Salt Lake | 1979 | 39% | 63% | 14,251 | 8 | 3 |
| 84116 | Rose Park and Westpointe | 1978 | 38% | 49% | 15,252 | 58 | 1 |
| 84117 | Holladay | 1975 | 38% | 34% | 11,345 | 12 | 5 |
| 84118 | Kearns and Taylorsville | 1979 | 28% | 16% | 12,466 | 1 | 0 |
| 84119 | West Valley City | 1985 | 23% | 43% | 17,080 | 5 | 2 |
| 84120 | West Valley City (west) | 1978 | 23% | 24% | 14,316 | 1 | 1 |
| 84121 | Cottonwood Heights | 1977 | 28% | 25% | 16,642 | 19 | 5 |
| 84123 | Murray (west) and Taylorsville | 1984 | 16% | 41% | 15,082 | 11 | 2 |
| 84124 | Holladay and Millcreek (east) | 1966 | 61% | 22% | 8,928 | 9 | 4 |
| 84128 | West Valley City (south) | 1993 | 5% | 12% | 8,599 | 0 | 0 |
| 84129 | Taylorsville | 1982 | 11% | 20% | 12,234 | 1 | 1 |
Census ACS 2020-2024 5-year estimates by ZIP Code Tabulation Area (B25001, B25003, B25034, B25035). OpenFEMA FIMA NFIP redacted claims by reported ZIP code, all years. Click a column to sort.
Federal major disaster declarations
| Incident began | Event | Type | Counties |
|---|---|---|---|
| September 7, 2020 | Straight-Line Winds | Severe Storm | Salt Lake, Davis |
| March 18, 2020 | Earthquake And Aftershocks | Earthquake | Salt Lake, Davis |
| January 20, 2020 | Covid-19 Pandemic | Biological | Salt Lake, Davis |
| November 30, 2011 | Severe Storm | Severe Storm | Davis |
| April 18, 2011 | Flooding | Flood | Salt Lake |
| August 11, 1999 | Tornado, Severe Thunderstorms, And Hail | Tornado | Salt Lake |
| August 17, 1984 | Severe Storms, Mudslides, Landslides & Flooding | Flood | Salt Lake, Davis |
| April 13, 1983 | Severe Storms, Landslides & Flooding | Flood | Salt Lake, Davis |
OpenFEMA Disaster Declarations Summaries, Salt Lake and Davis counties, major disasters only.
How we built this
Temperature and precipitation. Daily highs, lows, precipitation and snowfall at Salt Lake City International Airport (GHCN USW00024127) from NOAA's Applied Climate Information System, 1928 to October 28, 2026. Years missing more than ten days are left out, which leaves 97 full years. A night counts as a hard freeze when the daily minimum is 20°F or lower, the threshold from University of Illinois Building Research Council field tests on frozen pipes.
Humidity. NOAA NCEI Global Summary of the Day for the same airport (72572024127), daily mean temperature and dew point, 1973 to 2025. Relative humidity is our calculation from those two.
Claims and housing. OpenFEMA FIMA NFIP redacted claims and disaster declarations for Salt Lake and Davis counties. US Census ACS 2020-2024 5-year estimates by ZIP Code Tabulation Area. The NFIP data covers flood insurance only; burst pipes, water heaters and sewer backups are never in it.
Limits. One airport station on the valley floor doesn't describe the benches, which run colder at night. A pipe's risk depends on where it runs and how it is insulated as much as on the weather. Use this to understand the area, not to judge a particular house.
Using this data. Feel free to quote or republish this data under CC BY 4.0, with a link to this page.