Find your last frost date
Sowing and transplanting dates all count from one number: the average date of the last spring frost where you garden. Enter your ZIP code to find the nearest weather station, or open your state for every station NOAA reports.
Looking for the first fall frost? Look it up by ZIP code →
Nearest station with thirty years of frost data to the centre of that ZIP code.
- Average last frost
- Safe date (10% risk)
- Early date (90% risk)
- First fall frost
- Frost-free days
How to read the three dates
Average is the date by which, in half of the years between 1991 and 2020, the last 32 °F night had already happened. Safe is later: only one year in ten saw a frost after it, which is the date to transplant tomatoes and peppers, both killed by a single frost. Early is the risky end, with a frost after it in nine years out of ten.
Every figure is for the weather station, not for your garden. A valley bottom, a north slope or a spot near a lake can run a week or two either way. Cities are warmer than the countryside around them.
Where the numbers come from
The dates are NOAA's U.S. Climate Normals for 1991 to 2020, computed by the National Centers for Environmental Information for every station with thirty years of daily minimum temperatures. ZIP codes are matched to the nearest such station within 150 km using U.S. Census Bureau ZIP Code Tabulation Area centroids. Stations that never see a frost, such as much of south Florida, report no date and are left out.
Every state
Median across each state's stations, with the spread between its earliest and latest station. Open a state for the station list.
| Earliest to latest | |||
|---|---|---|---|
| Alabama | 118 | Mar 21 | Jan 31 – Apr 11 |
| Alaska | 163 | May 16 | Apr 4 – Jun 12 |
| Arizona | 174 | Mar 29 | Jan 4 – Jun 23 |
| Arkansas | 112 | Mar 27 | Mar 10 – Apr 15 |
| California | 332 | Feb 22 | Dec 29 – Jun 14 |
| Colorado | 210 | May 11 | Apr 14 – Jun 21 |
| Connecticut | 23 | Apr 25 | Apr 5 – May 11 |
| Delaware | 7 | Apr 7 | Mar 29 – Apr 11 |
| District of Columbia | 0 | — | — |
| Florida | 139 | Feb 1 | Jan 15 – Mar 21 |
| Georgia | 126 | Mar 21 | Feb 8 – Apr 26 |
| Hawaii | 2 | Jan 26 | Jan 26 – Apr 12 |
| Idaho | 127 | May 16 | Apr 2 – Jun 22 |
| Illinois | 170 | Apr 18 | Apr 2 – May 2 |
| Indiana | 117 | Apr 21 | Mar 29 – May 2 |
| Iowa | 150 | Apr 28 | Apr 10 – May 8 |
| Kansas | 176 | Apr 19 | Apr 4 – May 9 |
| Kentucky | 97 | Apr 15 | Mar 27 – May 2 |
| Louisiana | 98 | Mar 1 | Jan 22 – Mar 30 |
| Maine | 82 | May 8 | Apr 21 – Jun 2 |
| Maryland | 43 | Apr 8 | Mar 22 – May 9 |
| Massachusetts | 69 | Apr 27 | Apr 4 – May 17 |
| Michigan | 211 | May 8 | Apr 17 – Jun 7 |
| Minnesota | 179 | May 5 | Apr 15 – Jun 5 |
| Mississippi | 94 | Mar 16 | Feb 12 – Apr 9 |
| Missouri | 171 | Apr 12 | Mar 24 – Apr 27 |
| Montana | 216 | May 20 | Apr 30 – Jun 18 |
| Nebraska | 184 | May 2 | Apr 15 – May 30 |
| Nevada | 109 | May 12 | Jan 5 – Jun 16 |
| New Hampshire | 54 | May 8 | Apr 21 – May 31 |
| New Jersey | 48 | Apr 16 | Mar 26 – May 1 |
| New Mexico | 175 | Apr 29 | Mar 9 – Jun 19 |
| New York | 176 | May 4 | Mar 26 – Jun 2 |
| North Carolina | 187 | Apr 1 | Mar 1 – May 16 |
| North Dakota | 125 | May 13 | May 2 – May 24 |
| Ohio | 130 | Apr 24 | Apr 8 – May 10 |
| Oklahoma | 193 | Apr 5 | Mar 15 – Apr 26 |
| Oregon | 172 | Apr 22 | Jan 31 – Jun 11 |
| Pennsylvania | 160 | Apr 28 | Mar 30 – May 24 |
| Rhode Island | 11 | Apr 22 | Apr 7 – May 3 |
| South Carolina | 103 | Mar 26 | Feb 4 – Apr 26 |
| South Dakota | 166 | May 8 | Apr 26 – Jun 1 |
| Tennessee | 148 | Apr 7 | Mar 16 – May 22 |
| Texas | 476 | Mar 14 | Jan 3 – Apr 28 |
| Utah | 169 | May 11 | Mar 9 – Jun 21 |
| Vermont | 45 | May 13 | Apr 28 – Jun 1 |
| Virginia | 125 | Apr 14 | Mar 16 – May 12 |
| Washington | 154 | Apr 22 | Feb 26 – Jun 6 |
| West Virginia | 99 | Apr 26 | Apr 7 – May 15 |
| Wisconsin | 204 | May 5 | Apr 19 – Jun 3 |
| Wyoming | 129 | May 20 | Apr 28 – Jun 24 |
Last frost dates by USDA hardiness zone
A hardiness zone is built from the coldest winter night, not from the last spring frost, so two gardens in the same zone can be weeks apart. The table gives the median across ZIP codes in each half zone and the range that covers the middle 80% of them. Your own ZIP code above is the better answer.
| Zone | Median last frost | Median safe date | Typical range | Median first fall frost |
|---|---|---|---|---|
| Zone 3b | May 17 | May 31 | May 12 – May 28 | Sep 24 |
| Zone 4a | May 13 | May 27 | May 5 – May 25 | Sep 28 |
| Zone 4b | May 8 | May 22 | May 1 – May 26 | Oct 1 |
| Zone 5a | May 4 | May 17 | Apr 27 – May 23 | Oct 4 |
| Zone 5b | May 1 | May 16 | Apr 21 – May 18 | Oct 10 |
| Zone 6a | Apr 29 | May 14 | Apr 17 – May 12 | Oct 16 |
| Zone 6b | Apr 23 | May 9 | Apr 10 – May 6 | Oct 22 |
| Zone 7a | Apr 16 | May 3 | Apr 5 – Apr 29 | Oct 25 |
| Zone 7b | Apr 6 | Apr 22 | Mar 30 – Apr 19 | Nov 1 |
| Zone 8a | Mar 29 | Apr 14 | Mar 20 – Apr 8 | Nov 6 |
| Zone 8b | Mar 18 | Apr 6 | Mar 6 – Apr 7 | Nov 13 |
| Zone 9a | Mar 3 | Mar 25 | Feb 15 – Mar 21 | Nov 25 |
| Zone 9b | Feb 2 | Mar 5 | Jan 12 – Mar 3 | Dec 14 |
Zones 10 and warmer are left out. Frost there is rare, and the nearest weather station with frost records is often far from the garden, so a zone figure would mislead.
Zones from the 2023 USDA Plant Hardiness Zone Map ZIP code data by the PRISM Climate Group, Oregon State University. This table is derived from that data and is not the official USDA Plant Hardiness Zone Map.