Frost dates
Frost dates in Iowa
Typical last spring frost and first fall frost for 150 weather stations across Iowa, from NOAA’s 1991–2020 climate normals.
Last spring frost
Apr 19 – May 3
Typical across Iowa (middle: Apr 28)
First fall frost
Oct 3 – Oct 19
Typical across Iowa (middle: Oct 10)
Your own yard can differ by weeks from the nearest town. Get frost dates for your exact spot →
By town
| Station | Last spring frost | First fall frost | Frost-free days |
|---|---|---|---|
| Albia 3 NNE | Apr 24 | Oct 16 | 175 |
| Algona | Apr 30 | Oct 6 | 159 |
| Allerton | Apr 21 | Oct 19 | 181 |
| Allison | Apr 27 | Oct 8 | 164 |
| Ames 5 SE | Apr 26 | Oct 12 | 169 |
| Ames 8 WSW | Apr 23 | Oct 14 | 174 |
| Ames Municipal Airport | Apr 26 | Oct 8 | 165 |
| Anamosa 1 WNW | May 1 | Oct 4 | 156 |
| Anamosa 3 SSW | Apr 27 | Oct 13 | 169 |
| Ankeny | Apr 23 | Oct 15 | 175 |
| Atlantic 1 NE | Apr 30 | Oct 2 | 155 |
| Audubon | May 2 | Oct 3 | 154 |
| Battle Creek 3 NE | May 1 | Oct 1 | 153 |
| Beaconsfield | Apr 23 | Oct 17 | 177 |
| Bedford | Apr 24 | Oct 15 | 174 |
| Belle Plaine | Apr 28 | Oct 10 | 165 |
| Bellevue L&D 12 | Apr 25 | Oct 16 | 174 |
| Bloomfield | Apr 16 | Oct 22 | 189 |
| Boone | Apr 28 | Oct 12 | 167 |
| Britt 3 E | Apr 29 | Oct 7 | 161 |
| Burlington 2 S | Apr 18 | Oct 20 | 185 |
| Burlington Municipal Airport | Apr 15 | Oct 20 | 188 |
| Carroll | Apr 27 | Oct 10 | 166 |
| Cascade | Apr 28 | Oct 10 | 165 |
| Castana Experiment Farm | Apr 25 | Oct 12 | 170 |
| Cedar Rapids #1 | Apr 28 | Oct 12 | 167 |
| Cedar Rapids Municipal Airport | Apr 27 | Oct 11 | 167 |
| Centerville | Apr 28 | Oct 14 | 169 |
| Chariton 1 E | May 5 | Oct 5 | 153 |
| Charles City | Apr 30 | Oct 6 | 159 |
| Cherokee | May 4 | Oct 4 | 153 |
| Clarinda | Apr 25 | Oct 11 | 169 |
| Clarion | Apr 30 | Oct 10 | 163 |
| Clinton #1 | Apr 22 | Oct 16 | 177 |
| Coggon | May 3 | Oct 7 | 157 |
| Colo | Apr 24 | Oct 12 | 171 |
| Columbus Junction | Apr 26 | Oct 10 | 167 |
| Corning | Apr 27 | Oct 12 | 168 |
| Cresco 1 NE | May 8 | Oct 1 | 146 |
| Creston 2 SW | Apr 28 | Oct 11 | 166 |
| Dakota City | Apr 26 | Oct 12 | 169 |
| Davenport | Apr 21 | Oct 17 | 179 |
| Davenport | Apr 23 | Oct 15 | 175 |
| Decorah | May 3 | Oct 7 | 157 |
| Denison | Apr 27 | Oct 11 | 167 |
| Des Moines 17 E | Apr 21 | Oct 15 | 177 |
| Des Moines International Airport | Apr 18 | Oct 20 | 185 |
| Des Moines Wsfo-Johnston | Apr 19 | Oct 18 | 182 |
| Donnellson | Apr 17 | Oct 22 | 188 |
| Dubuque L&D 11 | Apr 19 | Oct 21 | 185 |
| Dubuque Regional Airport | Apr 28 | Oct 11 | 166 |
| Eldora | Apr 27 | Oct 10 | 166 |
| Elkader 6 SSW | May 8 | Oct 1 | 146 |
| Emmetsburg | Apr 27 | Oct 7 | 163 |
| Estherville 4 E | May 2 | Oct 3 | 154 |
| Estherville Municipal Airport | May 2 | Sep 30 | 151 |
| Fairfield | Apr 27 | Oct 12 | 168 |
| Fayette | May 4 | Oct 4 | 153 |
| Forest City 2 NNE | Apr 30 | Oct 7 | 160 |
| Fort Dodge 5 NNW | Apr 28 | Oct 8 | 163 |
| Fort Madison | Apr 12 | Oct 25 | 196 |
| Glenwood 3 SW | Apr 23 | Oct 11 | 171 |
| Greenfield | Apr 25 | Oct 12 | 170 |
| Grinnell 3 SW | May 3 | Oct 6 | 156 |
| Grundy Ctr | Apr 29 | Oct 9 | 163 |
| Guthrie Ctr | May 2 | Oct 3 | 154 |
| Guttenberg L&D 10 | Apr 21 | Oct 18 | 180 |
| Hampton | Apr 29 | Oct 9 | 163 |
| Harlan | Apr 27 | Oct 9 | 165 |
| Hawarden | May 1 | Oct 4 | 156 |
| Holstein | Apr 30 | Oct 9 | 162 |
| Humboldt Wtp | Apr 27 | Oct 9 | 165 |
| Ida Grove 5 NW | Apr 27 | Oct 12 | 168 |
| Independence #1 | Apr 30 | Oct 7 | 160 |
| Indianola 2 W | Apr 24 | Oct 12 | 171 |
| Iowa City | Apr 29 | Oct 9 | 163 |
| Iowa City Municipal Airport | Apr 21 | Oct 18 | 180 |
| Iowa Falls | Apr 28 | Oct 10 | 165 |
| Jefferson | Apr 26 | Oct 9 | 166 |
| Keokuk Lock Dam 19 | Apr 10 | Oct 27 | 200 |
| Keosauqua | Apr 26 | Oct 13 | 170 |
| Knoxville | Apr 20 | Oct 19 | 182 |
| Lake Park | Apr 30 | Oct 10 | 163 |
| Lamoni | Apr 17 | Oct 21 | 187 |
| Lamoni | Apr 16 | Oct 20 | 187 |
| Lamoni Municipal Airport | Apr 16 | Oct 21 | 188 |
| Le Claire L&D 14 | Apr 16 | Oct 25 | 192 |
| Le Mars | Apr 30 | Oct 4 | 157 |
| Leon 6 ESE | Apr 30 | Oct 8 | 161 |
| Little Sioux 2 NW | May 1 | Oct 3 | 155 |
| Logan | Apr 29 | Oct 8 | 162 |
| Lowden | Apr 27 | Oct 10 | 166 |
| Manchester #2 | May 3 | Oct 4 | 154 |
| Mapleton No.2 | May 3 | Oct 1 | 151 |
| Maquoketa | Apr 25 | Oct 14 | 172 |
| Marshalltown | Apr 28 | Oct 7 | 162 |
| Marshalltown Municipal Airport | Apr 30 | Oct 6 | 159 |
| Mason City | Apr 29 | Oct 7 | 161 |
| Mason City Municipal Airport | May 3 | Oct 1 | 151 |
| Milford 4 NW | May 1 | Oct 6 | 158 |
| Mount Ayr | Apr 25 | Oct 12 | 170 |
| Mount Pleasant 1 SSW | Apr 30 | Oct 10 | 163 |
| Muscatine | Apr 24 | Oct 14 | 173 |
| Muscatine 2 N | Apr 18 | Oct 22 | 187 |
| New Hampton | May 2 | Oct 5 | 156 |
| Newton | Apr 22 | Oct 17 | 178 |
| Northwood | May 4 | Oct 4 | 153 |
| Oakland | Apr 23 | Oct 14 | 174 |
| Oelwein 1 E | Apr 27 | Oct 13 | 169 |
| Oelwein 2 S | Apr 30 | Oct 9 | 162 |
| Onawa 3 NW | May 1 | Oct 3 | 155 |
| Osage | Apr 30 | Oct 9 | 162 |
| Osceola | Apr 29 | Oct 9 | 163 |
| Oskaloosa | Apr 21 | Oct 16 | 178 |
| Ottumwa Industrial Airport | Apr 23 | Oct 14 | 174 |
| Perry | Apr 25 | Oct 10 | 168 |
| Pocahontas | Apr 26 | Oct 7 | 164 |
| Postville | May 1 | Oct 3 | 155 |
| Primghar | Apr 29 | Oct 10 | 164 |
| Rathbun Dam | Apr 18 | Oct 23 | 188 |
| Red Oak | Apr 24 | Oct 13 | 172 |
| Rock Rapids | May 1 | Oct 4 | 156 |
| Rockwell City | Apr 26 | Oct 10 | 167 |
| Sac City | Apr 30 | Oct 6 | 159 |
| Sanborn | May 1 | Oct 7 | 159 |
| Sheldon | May 5 | Sep 28 | 146 |
| Shenandoah | Apr 20 | Oct 17 | 180 |
| Sibley | May 5 | Oct 3 | 151 |
| Sidney 1 SSE | Apr 19 | Oct 19 | 183 |
| Sigourney | Apr 24 | Oct 15 | 174 |
| Sioux City Ang | Apr 29 | Oct 7 | 161 |
| Sioux City Gateway Airport | Apr 29 | Oct 5 | 159 |
| Sioux Ctr 2 SE | Apr 30 | Oct 3 | 156 |
| Sioux Rapids 4 E | Apr 30 | Oct 5 | 158 |
| Spencer 1 N | May 1 | Oct 3 | 155 |
| Spencer Municipal Airport | May 2 | Oct 2 | 153 |
| Spirit Lake | Apr 28 | Oct 11 | 166 |
| Stanley | May 4 | Oct 1 | 150 |
| Storm Lake | Apr 25 | Oct 13 | 171 |
| Swea City 5 N | May 4 | Oct 1 | 150 |
| Tipton | Apr 21 | Oct 15 | 177 |
| Toledo 3 N | Apr 30 | Oct 9 | 162 |
| Tripoli | Apr 29 | Oct 9 | 163 |
| Vinton | May 3 | Oct 3 | 153 |
| Washington | Apr 28 | Oct 11 | 166 |
| Waterloo Municipal Airport | Apr 27 | Oct 10 | 166 |
| Waukon | May 2 | Oct 11 | 162 |
| Webster City | May 3 | Oct 2 | 152 |
| Williamsburg 1 E | Apr 28 | Oct 9 | 164 |
| Winterset 1 S | Apr 30 | Oct 3 | 156 |
Each date is the median: in half of years the frost comes earlier, in half later. Frost here means a low of 32°F or colder at the station. Low spots and valleys often frost a week or two earlier than these dates; hillsides and city centers later.
Source: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020. The Field almanac also shows how often frost comes early or late, and a reanalysis reading for your exact location.