Frost dates map
2088 NOAA weather stations, colored by the date with a 50% chance of frost (1991–2020 normals). Across all of them, the median station sees its last spring frost around Apr 26 and its first fall frost around Oct 17, a frost-free season of about 173 days.
Last spring frost (32°F, 50% chance). Darker dots: earlier spring.
- before Mar 1
- Mar 1–15
- Mar 16–31
- Apr 1–15
- Apr 16–30
- May 1–15
- May 16–31
- Jun 1 or later
Loading map…
Tap a dot for its frost dates, or anywhere on the map for the nearest stations within 50 miles. Pinch, the + and − buttons, or Ctrl + scroll zoom; drag to move once zoomed in. Keyboard: arrow keys move, + and − zoom, Enter picks the station at the center.
What the map shows
By region, spring frost ends first in the South (median station: Apr 1) and last in the West (May 9). The earliest last frost in spring on the map is at near Grand Canyon Village, AZ (Feb 9), the latest at McCall, ID (Jun 22). In fall, the first frost comes earliest at McCall, ID (Sep 2) and latest at near Grand Canyon Village, AZ (Dec 5).
The frost-free season runs from 72 days at McCall, ID to 295 days at near Grand Canyon Village, AZ. Dates inside one state can differ by weeks, so use the station closest to you.
“50% chance” means half of the years in the 1991–2020 record had the frost earlier and half later. Each station page also lists the 10% and 90% dates.
| Region | Stations | Last spring frost | First fall frost | Frost-free days |
|---|---|---|---|---|
| South | 529 | Apr 1 | Nov 3 | 215 |
| Midwest | 827 | Apr 29 | Oct 12 | 164 |
| Northeast | 209 | May 2 | Oct 14 | 163 |
| West | 523 | May 9 | Oct 4 | 147 |
Frost dates by state
| State | Stations | Last spring frost | First fall frost | Frost-free days |
|---|---|---|---|---|
| Alabama | 33 | Mar 23 | Nov 9 | 231 |
| Arizona | 29 | Apr 24 | Oct 25 | 183 |
| Arkansas | 51 | Mar 26 | Nov 6 | 227 |
| California | 29 | Apr 23 | Nov 5 | 197 |
| Colorado | 65 | May 8 | Oct 5 | 149 |
| Connecticut | 7 | Apr 19 | Oct 22 | 186 |
| Delaware | 3 | Apr 7 | Nov 4 | 209 |
| Florida | 7 | Mar 11 | Nov 21 | 258 |
| Georgia | 25 | Mar 23 | Nov 10 | 232 |
| Idaho | 34 | May 16 | Oct 2 | 137 |
| Illinois | 67 | Apr 19 | Oct 20 | 183 |
| Indiana | 51 | Apr 23 | Oct 20 | 180 |
| Iowa | 100 | Apr 28 | Oct 10 | 164 |
| Kansas | 74 | Apr 19 | Oct 20 | 182 |
| Kentucky | 18 | Apr 13 | Oct 27 | 196 |
| Louisiana | 16 | Mar 9 | Nov 17 | 254 |
| Maine | 28 | May 8 | Oct 4 | 149 |
| Maryland | 14 | Apr 13 | Oct 29 | 198 |
| Massachusetts | 19 | Apr 25 | Oct 21 | 177 |
| Michigan | 60 | May 9 | Oct 12 | 155 |
| Minnesota | 78 | May 5 | Oct 3 | 150 |
| Mississippi | 25 | Mar 17 | Nov 12 | 239 |
| Missouri | 66 | Apr 12 | Oct 24 | 194 |
| Montana | 90 | May 20 | Sep 22 | 124 |
| Nebraska | 75 | May 1 | Oct 9 | 159 |
| Nevada | 28 | May 20 | Sep 29 | 129 |
| New Hampshire | 16 | May 11 | Oct 2 | 143 |
| New Jersey | 13 | Apr 15 | Oct 29 | 193 |
| New Mexico | 42 | May 2 | Oct 15 | 163 |
| New York | 58 | May 6 | Oct 11 | 158 |
| North Carolina | 51 | Apr 6 | Nov 1 | 208 |
| North Dakota | 50 | May 13 | Sep 27 | 136 |
| Ohio | 56 | Apr 24 | Oct 22 | 181 |
| Oklahoma | 21 | Apr 6 | Oct 31 | 205 |
| Oregon | 48 | Apr 21 | Oct 25 | 186 |
| Pennsylvania | 55 | Apr 30 | Oct 20 | 173 |
| Rhode Island | 3 | Apr 25 | Oct 19 | 176 |
| South Carolina | 26 | Mar 28 | Nov 7 | 226 |
| South Dakota | 72 | May 8 | Oct 1 | 145 |
| Tennessee | 60 | Apr 7 | Oct 29 | 203 |
| Texas | 95 | Mar 20 | Nov 11 | 236 |
| Utah | 53 | May 8 | Oct 5 | 150 |
| Vermont | 10 | May 14 | Oct 1 | 140 |
| Virginia | 49 | Apr 15 | Oct 27 | 194 |
| Washington | 65 | Apr 22 | Oct 22 | 185 |
| West Virginia | 35 | Apr 23 | Oct 22 | 180 |
| Wisconsin | 78 | May 4 | Oct 8 | 155 |
| Wyoming | 40 | May 19 | Sep 24 | 126 |
Medians are taken over stations, not area: a state with many valley stations leans toward valley dates. State outlines: U.S. Census Bureau cartographic boundaries via us-atlas (ISC). Albers equal-area projection; Alaska, Hawaii and Puerto Rico have no stations on this site.