Frost Dates in Iowa
Across 150 NOAA weather stations in Iowa, the average last spring frost falls between April 10 at Keokuk Lock Dam 19 and May 8 at Elkader 6 SSW. At a typical Iowa station it is around April 28, with the first fall frost around October 10 and a frost-free season of about 164 days.
Find the frost dates for your ZIP code
A typical Iowa season
What shapes frost dates in Iowa
- The frost-free season ranges from 145 days at Sheldon to 198 days at Keokuk Lock Dam 19.
- Elevation matters: Sanborn, at 1,551 ft, averages its last frost on May 1, while Keokuk Lock Dam 19, at 527 ft, averages April 10.
- Gardens in valleys and low spots, where cold air settles, often frost a week or more later in spring than the nearest station.
Frost dates at major airports
| Station | Last frost | Safer date | First frost | Season (days) |
|---|---|---|---|---|
| Ames Muni Airport | Apr 26 | May 9 | Oct 8 | 164 |
| Burlington Muni Airport | Apr 15 | May 1 | Oct 20 | 187 |
| Cedar Rapids Muni Airport | Apr 27 | May 11 | Oct 11 | 165 |
| Davenport | Apr 23 | May 8 | Oct 15 | 174 |
| Des Moines 17 E | Apr 21 | May 5 | Oct 15 | 174 |
| Des Moines Intl Airport | Apr 18 | May 2 | Oct 20 | 184 |
| Dubuque Rgnl Airport | Apr 28 | May 12 | Oct 11 | 165 |
| Estherville Muni Airport | May 2 | May 14 | Sep 30 | 150 |
| Iowa City Muni Airport | Apr 21 | May 6 | Oct 18 | 180 |
| Lamoni | Apr 16 | May 2 | Oct 20 | 187 |
| Lamoni Muni Airport | Apr 16 | May 2 | Oct 21 | 186 |
| Marshalltown Muni Airport | Apr 30 | May 12 | Oct 6 | 159 |
| Mason City Muni Airport | May 3 | May 15 | Oct 1 | 150 |
| Ottumwa Industrial Airport | Apr 23 | May 7 | Oct 14 | 172 |
| Sioux City Gateway Airport | Apr 29 | May 14 | Oct 5 | 159 |
| Spencer Muni Airport | May 2 | May 15 | Oct 2 | 154 |
| Waterloo Muni Airport | Apr 27 | May 10 | Oct 10 | 165 |
All 150 weather stations in Iowa
| Station | Elevation (ft) | Last frost | Safer date | First frost | Season (days) |
|---|---|---|---|---|---|
| Albia 3 NNE | 880 | Apr 24 | May 9 | Oct 16 | 173 |
| Algona | 1,214 | Apr 30 | May 11 | Oct 6 | 160 |
| Allerton | 1,090 | Apr 21 | May 6 | Oct 19 | 178 |
| Allison | 1,038 | Apr 27 | May 8 | Oct 8 | 165 |
| Ames 5 SE | 870 | Apr 26 | May 8 | Oct 12 | 168 |
| Ames 8 WSW | 1,099 | Apr 23 | May 5 | Oct 14 | 173 |
| Ames Muni Airport | 930 | Apr 26 | May 9 | Oct 8 | 164 |
| Anamosa 1 WNW | 805 | May 1 | May 18 | Oct 4 | 154 |
| Anamosa 3 SSW | 906 | Apr 27 | May 10 | Oct 13 | 170 |
| Ankeny | 975 | Apr 23 | May 6 | Oct 15 | 173 |
| Atlantic 1 NE | 1,152 | Apr 30 | May 15 | Oct 2 | 153 |
| Audubon | 1,280 | May 2 | May 15 | Oct 3 | 154 |
| Battle Creek 3NE | 1,380 | May 1 | May 15 | Oct 1 | 153 |
| Beaconsfield | 1,215 | Apr 23 | May 6 | Oct 17 | 176 |
| Bedford | 1,190 | Apr 24 | May 6 | Oct 15 | 173 |
| Belle Plaine | 810 | Apr 28 | May 11 | Oct 10 | 165 |
| Bellevue L&d 12 | 603 | Apr 25 | May 11 | Oct 16 | 172 |
| Bloomfield | 858 | Apr 16 | Apr 30 | Oct 22 | 188 |
| Boone | 1,035 | Apr 28 | May 11 | Oct 12 | 165 |
| Britt 3E | 1,220 | Apr 29 | May 10 | Oct 7 | 161 |
| Burlington 2S | 690 | Apr 18 | May 3 | Oct 20 | 185 |
| Burlington Muni Airport | 692 | Apr 15 | May 1 | Oct 20 | 187 |
| Carroll | 1,240 | Apr 27 | May 8 | Oct 10 | 166 |
| Cascade | 814 | Apr 28 | May 12 | Oct 10 | 164 |
| Castana Exp Farm | 1,400 | Apr 25 | May 7 | Oct 12 | 170 |
| Cedar Rapids #1 | 813 | Apr 28 | May 13 | Oct 12 | 166 |
| Cedar Rapids Muni Airport | 868 | Apr 27 | May 11 | Oct 11 | 165 |
| Centerville | 905 | Apr 28 | May 11 | Oct 14 | 168 |
| Chariton 1 E | 965 | May 5 | May 19 | Oct 5 | 151 |
| Charles City | 993 | Apr 30 | May 14 | Oct 6 | 157 |
| Cherokee | 1,210 | May 4 | May 17 | Oct 4 | 152 |
| Clarinda | 980 | Apr 25 | May 7 | Oct 11 | 168 |
| Clarion | 1,156 | Apr 30 | May 12 | Oct 10 | 162 |
| Clinton #1 | 585 | Apr 22 | May 8 | Oct 16 | 175 |
| Coggon | 903 | May 3 | May 17 | Oct 7 | 156 |
| Colo | 1,000 | Apr 24 | May 7 | Oct 12 | 170 |
| Columbus Junction | 590 | Apr 26 | May 11 | Oct 10 | 167 |
| Corning | 1,190 | Apr 27 | May 11 | Oct 12 | 168 |
| Cresco 1 NE | 1,255 | May 8 | May 21 | Oct 1 | 147 |
| Creston 2 SW | 1,296 | Apr 28 | May 9 | Oct 11 | 164 |
| Dakota City | 1,110 | Apr 26 | May 7 | Oct 12 | 169 |
| Davenport | 754 | Apr 23 | May 8 | Oct 15 | 174 |
| Davenport Wfo | 750 | Apr 21 | May 7 | Oct 17 | 176 |
| Decorah | 860 | May 3 | May 16 | Oct 7 | 157 |
| Denison | 1,401 | Apr 27 | May 9 | Oct 11 | 166 |
| Des Moines 17 E | 921 | Apr 21 | May 5 | Oct 15 | 174 |
| Des Moines Intl Airport | 957 | Apr 18 | May 2 | Oct 20 | 184 |
| Des Moines Wsfo-Johnston | 959 | Apr 19 | May 3 | Oct 18 | 179 |
| Donnellson | 705 | Apr 17 | May 1 | Oct 22 | 187 |
| Dubuque L&d 11 | 620 | Apr 19 | May 4 | Oct 21 | 184 |
| Dubuque Rgnl Airport | 1,056 | Apr 28 | May 12 | Oct 11 | 165 |
| Eldora | 1,073 | Apr 27 | May 8 | Oct 10 | 165 |
| Elkader 6 SSW | 788 | May 8 | May 22 | Oct 1 | 146 |
| Emmetsburg | 1,225 | Apr 27 | May 9 | Oct 7 | 164 |
| Estherville 4E | 1,320 | May 2 | May 14 | Oct 3 | 153 |
| Estherville Muni Airport | 1,317 | May 2 | May 14 | Sep 30 | 150 |
| Fairfield | 740 | Apr 27 | May 14 | Oct 12 | 168 |
| Fayette | 1,145 | May 4 | May 17 | Oct 4 | 151 |
| Forest City 2 NNE | 1,280 | Apr 30 | May 10 | Oct 7 | 159 |
| Ft Dodge 5NNW | 1,115 | Apr 28 | May 9 | Oct 8 | 162 |
| Ft Madison | 530 | Apr 12 | Apr 26 | Oct 25 | 194 |
| Glenwood 3SW | 980 | Apr 23 | May 6 | Oct 11 | 170 |
| Greenfield | 1,316 | Apr 25 | May 7 | Oct 12 | 170 |
| Grinnell 3 SW | 905 | May 3 | May 17 | Oct 6 | 155 |
| Grundy Ctr | 985 | Apr 29 | May 12 | Oct 9 | 160 |
| Guthrie Ctr | 1,065 | May 2 | May 17 | Oct 3 | 153 |
| Guttenberg L&d 10 | 618 | Apr 21 | May 6 | Oct 18 | 178 |
| Hampton | 1,105 | Apr 29 | May 10 | Oct 9 | 162 |
| Harlan | 1,270 | Apr 27 | May 9 | Oct 9 | 165 |
| Hawarden | 1,190 | May 1 | May 14 | Oct 4 | 155 |
| Holstein | 1,370 | Apr 30 | May 11 | Oct 9 | 162 |
| Humboldt Wtp | 1,100 | Apr 27 | May 7 | Oct 9 | 166 |
| Ida Grove 5NW | 1,320 | Apr 27 | May 11 | Oct 12 | 167 |
| Independence #1 | 1,010 | Apr 30 | May 12 | Oct 7 | 159 |
| Indianola 2W | 924 | Apr 24 | May 8 | Oct 12 | 168 |
| Iowa City | 640 | Apr 29 | May 14 | Oct 9 | 162 |
| Iowa City Muni Airport | 650 | Apr 21 | May 6 | Oct 18 | 180 |
| Iowa Falls | 1,055 | Apr 28 | May 11 | Oct 10 | 164 |
| Jefferson | 1,055 | Apr 26 | May 8 | Oct 9 | 164 |
| Keokuk Lock Dam 19 | 527 | Apr 10 | Apr 26 | Oct 27 | 198 |
| Keosauqua | 629 | Apr 26 | May 11 | Oct 13 | 169 |
| Knoxville | 895 | Apr 20 | May 4 | Oct 19 | 180 |
| Lake Park | 1,465 | Apr 30 | May 11 | Oct 10 | 164 |
| Lamoni | 1,128 | Apr 17 | May 1 | Oct 21 | 184 |
| Lamoni | 1,168 | Apr 16 | May 2 | Oct 20 | 187 |
| Lamoni Muni Airport | 1,131 | Apr 16 | May 2 | Oct 21 | 186 |
| Le Claire L&d 14 | 577 | Apr 16 | Apr 30 | Oct 25 | 190 |
| Le Mars | 1,195 | Apr 30 | May 12 | Oct 4 | 157 |
| Leon 6 ESE | 1,000 | Apr 30 | May 15 | Oct 8 | 161 |
| Little Sioux 2 NW | 1,025 | May 1 | May 12 | Oct 3 | 155 |
| Logan | 990 | Apr 29 | May 13 | Oct 8 | 162 |
| Lowden | 738 | Apr 27 | May 13 | Oct 10 | 165 |
| Manchester #2 | 990 | May 3 | May 16 | Oct 4 | 154 |
| Mapleton NO.2 | 1,200 | May 3 | May 16 | Oct 1 | 151 |
| Maquoketa | 668 | Apr 25 | May 9 | Oct 14 | 171 |
| Marshalltown | 870 | Apr 28 | May 11 | Oct 7 | 162 |
| Marshalltown Muni Airport | 974 | Apr 30 | May 12 | Oct 6 | 159 |
| Mason City | 1,105 | Apr 29 | May 9 | Oct 7 | 161 |
| Mason City Muni Airport | 1,225 | May 3 | May 15 | Oct 1 | 150 |
| Milford 4 NW | 1,402 | May 1 | May 14 | Oct 6 | 158 |
| Mt Ayr | 1,140 | Apr 25 | May 9 | Oct 12 | 169 |
| Mt Pleasant 1 SSW | 730 | Apr 30 | May 14 | Oct 10 | 163 |
| Muscatine | 549 | Apr 24 | May 9 | Oct 14 | 172 |
| Muscatine 2N | 680 | Apr 18 | May 2 | Oct 22 | 184 |
| New Hampton | 1,148 | May 2 | May 14 | Oct 5 | 155 |
| Newton | 960 | Apr 22 | May 4 | Oct 17 | 174 |
| Northwood | 1,190 | May 4 | May 16 | Oct 4 | 152 |
| Oakland | 1,260 | Apr 23 | May 5 | Oct 14 | 174 |
| Oelwein 1E | 1,165 | Apr 27 | May 10 | Oct 13 | 169 |
| Oelwein 2 S | 1,010 | Apr 30 | May 13 | Oct 9 | 163 |
| Onawa 3NW | 1,060 | May 1 | May 13 | Oct 3 | 154 |
| Osage | 1,170 | Apr 30 | May 12 | Oct 9 | 163 |
| Osceola | 1,028 | Apr 29 | May 11 | Oct 9 | 162 |
| Oskaloosa | 830 | Apr 21 | May 4 | Oct 16 | 176 |
| Ottumwa Industrial Airport | 842 | Apr 23 | May 7 | Oct 14 | 172 |
| Perry | 950 | Apr 25 | May 8 | Oct 10 | 166 |
| Pocahontas | 1,212 | Apr 26 | May 8 | Oct 7 | 164 |
| Postville | 1,165 | May 1 | May 14 | Oct 3 | 153 |
| Primghar | 1,520 | Apr 29 | May 11 | Oct 10 | 163 |
| Rathbun Dam | 965 | Apr 18 | May 2 | Oct 23 | 187 |
| Red Oak | 1,040 | Apr 24 | May 8 | Oct 13 | 169 |
| Rock Rapids | 1,350 | May 1 | May 13 | Oct 4 | 156 |
| Rockwell City | 1,214 | Apr 26 | May 6 | Oct 10 | 167 |
| Sac City | 1,210 | Apr 30 | May 11 | Oct 6 | 158 |
| Sanborn | 1,551 | May 1 | May 13 | Oct 7 | 160 |
| Sheldon | 1,420 | May 5 | May 18 | Sep 28 | 145 |
| Shenandoah | 999 | Apr 20 | May 3 | Oct 17 | 179 |
| Sibley | 1,529 | May 5 | May 17 | Oct 3 | 152 |
| Sidney 1SSE | 1,140 | Apr 19 | May 2 | Oct 19 | 182 |
| Sigourney | 732 | Apr 24 | May 9 | Oct 15 | 172 |
| Sioux City Ang | 1,100 | Apr 29 | May 11 | Oct 7 | 161 |
| Sioux City Gateway Airport | 1,095 | Apr 29 | May 14 | Oct 5 | 159 |
| Sioux Ctr 2 SE | 1,360 | Apr 30 | May 12 | Oct 3 | 154 |
| Sioux Rapids 4 E | 1,420 | Apr 30 | May 11 | Oct 5 | 159 |
| Spencer 1 N | 1,326 | May 1 | May 14 | Oct 3 | 154 |
| Spencer Muni Airport | 1,338 | May 2 | May 15 | Oct 2 | 154 |
| Spirit Lake | 1,420 | Apr 28 | May 9 | Oct 11 | 164 |
| Stanley | 1,114 | May 4 | May 15 | Oct 1 | 150 |
| Storm Lake | 1,442 | Apr 25 | May 7 | Oct 13 | 170 |
| Swea City 5N | 1,180 | May 4 | May 14 | Oct 1 | 150 |
| Tipton | 820 | Apr 21 | May 4 | Oct 15 | 175 |
| Toledo 3N | 935 | Apr 30 | May 11 | Oct 9 | 162 |
| Tripoli | 1,055 | Apr 29 | May 9 | Oct 9 | 162 |
| Vinton | 850 | May 3 | May 17 | Oct 3 | 151 |
| Washington | 687 | Apr 28 | May 11 | Oct 11 | 165 |
| Waterloo Muni Airport | 868 | Apr 27 | May 10 | Oct 10 | 165 |
| Waukon | 1,275 | May 2 | May 16 | Oct 11 | 161 |
| Webster City | 1,072 | May 3 | May 16 | Oct 2 | 150 |
| Williamsburg 1E | 780 | Apr 28 | May 12 | Oct 9 | 164 |
| Winterset 1S | 1,100 | Apr 30 | May 11 | Oct 3 | 157 |
No station matches that name. Try a nearby town, or look up your ZIP code above.
Last frost and first frost are averages (a 50% chance of frost later in spring or earlier in fall). Safer date is the spring date with only a 10% chance of a later frost.
Using these dates
Plant hardy crops like peas and spinach several weeks before your last frost, and tender crops like tomatoes and peppers after it, once nights stay above 50°F. The Seed Starting Calculator turns your frost date into sowing and planting dates, and When to Plant Tomatoes explains the timing in detail.
Data: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, 32°F threshold.
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