Last frost dates in Iowa
150 NOAA weather stations in Iowa have thirty years of frost records. The median station sees its last 32 °F night around Apr 28; across the state that ranges from Apr 10 to May 8, so pick the station nearest you rather than a state-wide figure.
| Plan sowing from this date | ||||||
|---|---|---|---|---|---|---|
| KEOKUK LOCK DAM 19 | Apr 10 | Apr 26 | Mar 30 | Oct 27 | 198 | Plan sowing from this date → |
| FT MADISON | Apr 12 | Apr 26 | Apr 1 | Oct 25 | 194 | Plan sowing from this date → |
| BURLINGTON MUNI AP | Apr 15 | May 1 | Apr 2 | Oct 20 | 187 | Plan sowing from this date → |
| BLOOMFIELD | Apr 16 | Apr 30 | Apr 1 | Oct 22 | 188 | Plan sowing from this date → |
| LAMONI | Apr 16 | May 2 | Apr 2 | Oct 20 | 187 | Plan sowing from this date → |
| LAMONI MUNI AP | Apr 16 | May 2 | Apr 2 | Oct 21 | 186 | Plan sowing from this date → |
| LE CLAIRE L&D 14 | Apr 16 | Apr 30 | Apr 2 | Oct 25 | 190 | Plan sowing from this date → |
| DONNELLSON | Apr 17 | May 1 | Apr 4 | Oct 22 | 187 | Plan sowing from this date → |
| LAMONI | Apr 17 | May 1 | Apr 4 | Oct 21 | 184 | Plan sowing from this date → |
| BURLINGTON 2S | Apr 18 | May 3 | Apr 3 | Oct 20 | 185 | Plan sowing from this date → |
| DES MOINES INTL AP | Apr 18 | May 2 | Apr 4 | Oct 20 | 184 | Plan sowing from this date → |
| MUSCATINE 2N | Apr 18 | May 2 | Apr 4 | Oct 22 | 184 | Plan sowing from this date → |
| RATHBUN DAM | Apr 18 | May 2 | Apr 4 | Oct 23 | 187 | Plan sowing from this date → |
| DES MOINES WSFO-JOHNSTON | Apr 19 | May 3 | Apr 5 | Oct 18 | 179 | Plan sowing from this date → |
| DUBUQUE L&D 11 | Apr 19 | May 4 | Apr 4 | Oct 21 | 184 | Plan sowing from this date → |
| SIDNEY 1SSE | Apr 19 | May 2 | Apr 5 | Oct 19 | 182 | Plan sowing from this date → |
| KNOXVILLE | Apr 20 | May 4 | Apr 6 | Oct 19 | 180 | Plan sowing from this date → |
| SHENANDOAH | Apr 20 | May 3 | Apr 5 | Oct 17 | 179 | Plan sowing from this date → |
| ALLERTON | Apr 21 | May 6 | Apr 7 | Oct 19 | 178 | Plan sowing from this date → |
| DAVENPORT WFO | Apr 21 | May 7 | Apr 7 | Oct 17 | 176 | Plan sowing from this date → |
| DES MOINES 17 E | Apr 21 | May 5 | Apr 7 | Oct 15 | 174 | Plan sowing from this date → |
| GUTTENBERG L&D 10 | Apr 21 | May 6 | Apr 7 | Oct 18 | 178 | Plan sowing from this date → |
| IOWA CITY MUNI AP | Apr 21 | May 6 | Apr 5 | Oct 18 | 180 | Plan sowing from this date → |
| OSKALOOSA | Apr 21 | May 4 | Apr 8 | Oct 16 | 176 | Plan sowing from this date → |
| TIPTON | Apr 21 | May 4 | Apr 8 | Oct 15 | 175 | Plan sowing from this date → |
| CLINTON #1 | Apr 22 | May 8 | Apr 9 | Oct 16 | 175 | Plan sowing from this date → |
| NEWTON | Apr 22 | May 4 | Apr 8 | Oct 17 | 174 | Plan sowing from this date → |
| AMES 8 WSW | Apr 23 | May 5 | Apr 7 | Oct 14 | 173 | Plan sowing from this date → |
| ANKENY | Apr 23 | May 6 | Apr 8 | Oct 15 | 173 | Plan sowing from this date → |
| BEACONSFIELD | Apr 23 | May 6 | Apr 7 | Oct 17 | 176 | Plan sowing from this date → |
| DAVENPORT | Apr 23 | May 8 | Apr 8 | Oct 15 | 174 | Plan sowing from this date → |
| GLENWOOD 3SW | Apr 23 | May 6 | Apr 9 | Oct 11 | 170 | Plan sowing from this date → |
| OAKLAND | Apr 23 | May 5 | Apr 10 | Oct 14 | 174 | Plan sowing from this date → |
| OTTUMWA INDUSTRIAL AP | Apr 23 | May 7 | Apr 9 | Oct 14 | 172 | Plan sowing from this date → |
| ALBIA 3 NNE | Apr 24 | May 9 | Apr 8 | Oct 16 | 173 | Plan sowing from this date → |
| BEDFORD | Apr 24 | May 6 | Apr 9 | Oct 15 | 173 | Plan sowing from this date → |
| COLO | Apr 24 | May 7 | Apr 9 | Oct 12 | 170 | Plan sowing from this date → |
| INDIANOLA 2W | Apr 24 | May 8 | Apr 11 | Oct 12 | 168 | Plan sowing from this date → |
| MUSCATINE | Apr 24 | May 9 | Apr 9 | Oct 14 | 172 | Plan sowing from this date → |
| RED OAK | Apr 24 | May 8 | Apr 10 | Oct 13 | 169 | Plan sowing from this date → |
| SIGOURNEY | Apr 24 | May 9 | Apr 9 | Oct 15 | 172 | Plan sowing from this date → |
| BELLEVUE L&D 12 | Apr 25 | May 11 | Apr 10 | Oct 16 | 172 | Plan sowing from this date → |
| CASTANA EXP FARM | Apr 25 | May 7 | Apr 11 | Oct 12 | 170 | Plan sowing from this date → |
| CLARINDA | Apr 25 | May 7 | Apr 11 | Oct 11 | 168 | Plan sowing from this date → |
| GREENFIELD | Apr 25 | May 7 | Apr 12 | Oct 12 | 170 | Plan sowing from this date → |
| MAQUOKETA | Apr 25 | May 9 | Apr 11 | Oct 14 | 171 | Plan sowing from this date → |
| MT AYR | Apr 25 | May 9 | Apr 10 | Oct 12 | 169 | Plan sowing from this date → |
| PERRY | Apr 25 | May 8 | Apr 12 | Oct 10 | 166 | Plan sowing from this date → |
| STORM LAKE | Apr 25 | May 7 | Apr 11 | Oct 13 | 170 | Plan sowing from this date → |
| AMES 5 SE | Apr 26 | May 8 | Apr 11 | Oct 12 | 168 | Plan sowing from this date → |
| AMES MUNI AP | Apr 26 | May 9 | Apr 11 | Oct 8 | 164 | Plan sowing from this date → |
| COLUMBUS JUNCTION | Apr 26 | May 11 | Apr 11 | Oct 10 | 167 | Plan sowing from this date → |
| DAKOTA CITY | Apr 26 | May 7 | Apr 11 | Oct 12 | 169 | Plan sowing from this date → |
| JEFFERSON | Apr 26 | May 8 | Apr 12 | Oct 9 | 164 | Plan sowing from this date → |
| KEOSAUQUA | Apr 26 | May 11 | Apr 10 | Oct 13 | 169 | Plan sowing from this date → |
| POCAHONTAS | Apr 26 | May 8 | Apr 11 | Oct 7 | 164 | Plan sowing from this date → |
| ROCKWELL CITY | Apr 26 | May 6 | Apr 11 | Oct 10 | 167 | Plan sowing from this date → |
| ALLISON | Apr 27 | May 8 | Apr 12 | Oct 8 | 165 | Plan sowing from this date → |
| ANAMOSA 3 SSW | Apr 27 | May 10 | Apr 12 | Oct 13 | 170 | Plan sowing from this date → |
| CARROLL | Apr 27 | May 8 | Apr 14 | Oct 10 | 166 | Plan sowing from this date → |
| CEDAR RAPIDS MUNI AP | Apr 27 | May 11 | Apr 13 | Oct 11 | 165 | Plan sowing from this date → |
| CORNING | Apr 27 | May 11 | Apr 13 | Oct 12 | 168 | Plan sowing from this date → |
| DENISON | Apr 27 | May 9 | Apr 13 | Oct 11 | 166 | Plan sowing from this date → |
| ELDORA | Apr 27 | May 8 | Apr 13 | Oct 10 | 165 | Plan sowing from this date → |
| EMMETSBURG | Apr 27 | May 9 | Apr 11 | Oct 7 | 164 | Plan sowing from this date → |
| FAIRFIELD | Apr 27 | May 14 | Apr 13 | Oct 12 | 168 | Plan sowing from this date → |
| HARLAN | Apr 27 | May 9 | Apr 12 | Oct 9 | 165 | Plan sowing from this date → |
| HUMBOLDT WTP | Apr 27 | May 7 | Apr 15 | Oct 9 | 166 | Plan sowing from this date → |
| IDA GROVE 5NW | Apr 27 | May 11 | Apr 12 | Oct 12 | 167 | Plan sowing from this date → |
| LOWDEN | Apr 27 | May 13 | Apr 11 | Oct 10 | 165 | Plan sowing from this date → |
| OELWEIN 1E | Apr 27 | May 10 | Apr 12 | Oct 13 | 169 | Plan sowing from this date → |
| WATERLOO MUNI AP | Apr 27 | May 10 | Apr 11 | Oct 10 | 165 | Plan sowing from this date → |
| BELLE PLAINE | Apr 28 | May 11 | Apr 14 | Oct 10 | 165 | Plan sowing from this date → |
| BOONE | Apr 28 | May 11 | Apr 13 | Oct 12 | 165 | Plan sowing from this date → |
| CASCADE | Apr 28 | May 12 | Apr 12 | Oct 10 | 164 | Plan sowing from this date → |
| CEDAR RAPIDS #1 | Apr 28 | May 13 | Apr 14 | Oct 12 | 166 | Plan sowing from this date → |
| CENTERVILLE | Apr 28 | May 11 | Apr 13 | Oct 14 | 168 | Plan sowing from this date → |
| CRESTON 2 SW | Apr 28 | May 9 | Apr 14 | Oct 11 | 164 | Plan sowing from this date → |
| DUBUQUE RGNL AP | Apr 28 | May 12 | Apr 13 | Oct 11 | 165 | Plan sowing from this date → |
| FT DODGE 5NNW | Apr 28 | May 9 | Apr 13 | Oct 8 | 162 | Plan sowing from this date → |
| IOWA FALLS | Apr 28 | May 11 | Apr 13 | Oct 10 | 164 | Plan sowing from this date → |
| MARSHALLTOWN | Apr 28 | May 11 | Apr 13 | Oct 7 | 162 | Plan sowing from this date → |
| SPIRIT LAKE | Apr 28 | May 9 | Apr 14 | Oct 11 | 164 | Plan sowing from this date → |
| WASHINGTON | Apr 28 | May 11 | Apr 13 | Oct 11 | 165 | Plan sowing from this date → |
| WILLIAMSBURG 1E | Apr 28 | May 12 | Apr 14 | Oct 9 | 164 | Plan sowing from this date → |
| BRITT 3E | Apr 29 | May 10 | Apr 14 | Oct 7 | 161 | Plan sowing from this date → |
| GRUNDY CTR | Apr 29 | May 12 | Apr 15 | Oct 9 | 160 | Plan sowing from this date → |
| HAMPTON | Apr 29 | May 10 | Apr 15 | Oct 9 | 162 | Plan sowing from this date → |
| IOWA CITY | Apr 29 | May 14 | Apr 14 | Oct 9 | 162 | Plan sowing from this date → |
| LOGAN | Apr 29 | May 13 | Apr 15 | Oct 8 | 162 | Plan sowing from this date → |
| MASON CITY | Apr 29 | May 9 | Apr 14 | Oct 7 | 161 | Plan sowing from this date → |
| OSCEOLA | Apr 29 | May 11 | Apr 13 | Oct 9 | 162 | Plan sowing from this date → |
| PRIMGHAR | Apr 29 | May 11 | Apr 13 | Oct 10 | 163 | Plan sowing from this date → |
| SIOUX CITY ANG | Apr 29 | May 11 | Apr 15 | Oct 7 | 161 | Plan sowing from this date → |
| SIOUX CITY GATEWAY AP | Apr 29 | May 14 | Apr 16 | Oct 5 | 159 | Plan sowing from this date → |
| TRIPOLI | Apr 29 | May 9 | Apr 14 | Oct 9 | 162 | Plan sowing from this date → |
| ALGONA | Apr 30 | May 11 | Apr 16 | Oct 6 | 160 | Plan sowing from this date → |
| ATLANTIC 1 NE | Apr 30 | May 15 | Apr 17 | Oct 2 | 153 | Plan sowing from this date → |
| CHARLES CITY | Apr 30 | May 14 | Apr 15 | Oct 6 | 157 | Plan sowing from this date → |
| CLARION | Apr 30 | May 12 | Apr 17 | Oct 10 | 162 | Plan sowing from this date → |
| FOREST CITY 2 NNE | Apr 30 | May 10 | Apr 14 | Oct 7 | 159 | Plan sowing from this date → |
| HOLSTEIN | Apr 30 | May 11 | Apr 15 | Oct 9 | 162 | Plan sowing from this date → |
| INDEPENDENCE #1 | Apr 30 | May 12 | Apr 16 | Oct 7 | 159 | Plan sowing from this date → |
| LAKE PARK | Apr 30 | May 11 | Apr 12 | Oct 10 | 164 | Plan sowing from this date → |
| LE MARS | Apr 30 | May 12 | Apr 17 | Oct 4 | 157 | Plan sowing from this date → |
| LEON 6 ESE | Apr 30 | May 15 | Apr 16 | Oct 8 | 161 | Plan sowing from this date → |
| MARSHALLTOWN MUNI AP | Apr 30 | May 12 | Apr 15 | Oct 6 | 159 | Plan sowing from this date → |
| MT PLEASANT 1 SSW | Apr 30 | May 14 | Apr 13 | Oct 10 | 163 | Plan sowing from this date → |
| OELWEIN 2 S | Apr 30 | May 13 | Apr 14 | Oct 9 | 163 | Plan sowing from this date → |
| OSAGE | Apr 30 | May 12 | Apr 14 | Oct 9 | 163 | Plan sowing from this date → |
| SAC CITY | Apr 30 | May 11 | Apr 15 | Oct 6 | 158 | Plan sowing from this date → |
| SIOUX CTR 2 SE | Apr 30 | May 12 | Apr 17 | Oct 3 | 154 | Plan sowing from this date → |
| SIOUX RAPIDS 4 E | Apr 30 | May 11 | Apr 14 | Oct 5 | 159 | Plan sowing from this date → |
| TOLEDO 3N | Apr 30 | May 11 | Apr 15 | Oct 9 | 162 | Plan sowing from this date → |
| WINTERSET 1S | Apr 30 | May 11 | Apr 17 | Oct 3 | 157 | Plan sowing from this date → |
| ANAMOSA 1 WNW | May 1 | May 18 | Apr 18 | Oct 4 | 154 | Plan sowing from this date → |
| BATTLE CREEK 3NE | May 1 | May 15 | Apr 18 | Oct 1 | 153 | Plan sowing from this date → |
| HAWARDEN | May 1 | May 14 | Apr 17 | Oct 4 | 155 | Plan sowing from this date → |
| LITTLE SIOUX 2 NW | May 1 | May 12 | Apr 17 | Oct 3 | 155 | Plan sowing from this date → |
| MILFORD 4 NW | May 1 | May 14 | Apr 17 | Oct 6 | 158 | Plan sowing from this date → |
| ONAWA 3NW | May 1 | May 13 | Apr 19 | Oct 3 | 154 | Plan sowing from this date → |
| POSTVILLE | May 1 | May 14 | Apr 18 | Oct 3 | 153 | Plan sowing from this date → |
| ROCK RAPIDS | May 1 | May 13 | Apr 18 | Oct 4 | 156 | Plan sowing from this date → |
| SANBORN | May 1 | May 13 | Apr 16 | Oct 7 | 160 | Plan sowing from this date → |
| SPENCER 1 N | May 1 | May 14 | Apr 18 | Oct 3 | 154 | Plan sowing from this date → |
| AUDUBON | May 2 | May 15 | Apr 19 | Oct 3 | 154 | Plan sowing from this date → |
| ESTHERVILLE 4E | May 2 | May 14 | Apr 18 | Oct 3 | 153 | Plan sowing from this date → |
| ESTHERVILLE MUNI AP | May 2 | May 14 | Apr 19 | Sep 30 | 150 | Plan sowing from this date → |
| GUTHRIE CTR | May 2 | May 17 | Apr 18 | Oct 3 | 153 | Plan sowing from this date → |
| NEW HAMPTON | May 2 | May 14 | Apr 17 | Oct 5 | 155 | Plan sowing from this date → |
| SPENCER MUNI AP | May 2 | May 15 | Apr 17 | Oct 2 | 154 | Plan sowing from this date → |
| WAUKON | May 2 | May 16 | Apr 17 | Oct 11 | 161 | Plan sowing from this date → |
| COGGON | May 3 | May 17 | Apr 18 | Oct 7 | 156 | Plan sowing from this date → |
| DECORAH | May 3 | May 16 | Apr 19 | Oct 7 | 157 | Plan sowing from this date → |
| GRINNELL 3 SW | May 3 | May 17 | Apr 19 | Oct 6 | 155 | Plan sowing from this date → |
| MANCHESTER #2 | May 3 | May 16 | Apr 18 | Oct 4 | 154 | Plan sowing from this date → |
| MAPLETON NO.2 | May 3 | May 16 | Apr 21 | Oct 1 | 151 | Plan sowing from this date → |
| MASON CITY MUNI AP | May 3 | May 15 | Apr 19 | Oct 1 | 150 | Plan sowing from this date → |
| VINTON | May 3 | May 17 | Apr 21 | Oct 3 | 151 | Plan sowing from this date → |
| WEBSTER CITY | May 3 | May 16 | Apr 20 | Oct 2 | 150 | Plan sowing from this date → |
| CHEROKEE | May 4 | May 17 | Apr 20 | Oct 4 | 152 | Plan sowing from this date → |
| FAYETTE | May 4 | May 17 | Apr 20 | Oct 4 | 151 | Plan sowing from this date → |
| NORTHWOOD | May 4 | May 16 | Apr 21 | Oct 4 | 152 | Plan sowing from this date → |
| STANLEY | May 4 | May 15 | Apr 21 | Oct 1 | 150 | Plan sowing from this date → |
| SWEA CITY 5N | May 4 | May 14 | Apr 21 | Oct 1 | 150 | Plan sowing from this date → |
| CHARITON 1 E | May 5 | May 19 | Apr 21 | Oct 5 | 151 | Plan sowing from this date → |
| SHELDON | May 5 | May 18 | Apr 24 | Sep 28 | 145 | Plan sowing from this date → |
| SIBLEY | May 5 | May 17 | Apr 22 | Oct 3 | 152 | Plan sowing from this date → |
| CRESCO 1 NE | May 8 | May 21 | Apr 25 | Oct 1 | 147 | Plan sowing from this date → |
| ELKADER 6 SSW | May 8 | May 22 | Apr 24 | Oct 1 | 146 | Plan sowing from this date → |
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.