Iowa frost dates
The typical last spring frost ranges from Apr 18 in Des Moines to Apr 28 in Cedar Rapids.
3 of the 3 Iowa cities listed have typical frost dates. The longest frost-free season is 184 days in Davenport; the shortest is 166 days in Cedar Rapids. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Cedar Rapids | Apr 28 | May 13 | Oct 12 | Sep 29 | Apr 17 / Oct 22 | 166 days |
| Davenport | Apr 19 | May 4 | Oct 22 | Oct 7 | Apr 8 / Oct 31 | 184 days |
| Des Moines | Apr 18 | May 2 | Oct 20 | Oct 4 | Apr 8 / Oct 30 | 184 days |
Reading the table: Davenport
In Davenport, the last spring frost typically comes around Apr 19: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 4, 15 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Oct 22, and in 1 year in 10 before Oct 7. Hard freezes (28°F) usually end earlier in spring and start later in fall: around Apr 8 and Oct 31 in Davenport.
Frost dates at more Iowa weather stations
NOAA stations across Iowa used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Algona | 1,214 ft | Apr 30 (1 in 10 after May 11) | Oct 6 (before Sep 23) |
| Allison | 1,038 ft | Apr 27 (1 in 10 after May 8) | Oct 8 (before Sep 24) |
| Ames Muni Airport | 930 ft | Apr 26 (1 in 10 after May 9) | Oct 8 (before Sep 23) |
| Ankeny | 975 ft | Apr 23 (1 in 10 after May 6) | Oct 15 (before Sep 30) |
| Atlantic 1 Ne | 1,152 ft | Apr 30 (1 in 10 after May 15) | Oct 2 (before Sep 17) |
| Audubon | 1,280 ft | May 2 (1 in 10 after May 15) | Oct 3 (before Sep 19) |
| Belle Plaine | 810 ft | Apr 28 (1 in 10 after May 11) | Oct 10 (before Sep 26) |
| Bloomfield | 858 ft | Apr 16 (1 in 10 after Apr 30) | Oct 22 (before Oct 5) |
| Boone | 1,035 ft | Apr 28 (1 in 10 after May 11) | Oct 12 (before Sep 28) |
| Burlington Muni Airport | 692 ft | Apr 15 (1 in 10 after May 1) | Oct 20 (before Oct 6) |
| Carroll | 1,240 ft | Apr 27 (1 in 10 after May 8) | Oct 10 (before Sep 25) |
| Cascade | 814 ft | Apr 28 (1 in 10 after May 12) | Oct 10 (before Sep 28) |
| Cedar Rapids Muni Airport | 868 ft | Apr 27 (1 in 10 after May 11) | Oct 11 (before Sep 25) |
| Centerville | 905 ft | Apr 28 (1 in 10 after May 11) | Oct 14 (before Sep 26) |
| Chariton 1 E | 965 ft | May 5 (1 in 10 after May 19) | Oct 5 (before Sep 20) |
| Cherokee | 1,210 ft | May 4 (1 in 10 after May 17) | Oct 4 (before Sep 20) |
| Clarinda | 980 ft | Apr 25 (1 in 10 after May 7) | Oct 11 (before Sep 26) |
| Clinton #1 | 585 ft | Apr 22 (1 in 10 after May 8) | Oct 16 (before Oct 2) |
| Creston 2 Sw | 1,296 ft | Apr 28 (1 in 10 after May 9) | Oct 11 (before Sep 24) |
| Davenport | 754 ft | Apr 23 (1 in 10 after May 8) | Oct 15 (before Oct 1) |
| Denison | 1,401 ft | Apr 27 (1 in 10 after May 9) | Oct 11 (before Sep 27) |
| Dubuque L&D 11 | 620 ft | Apr 19 (1 in 10 after May 4) | Oct 21 (before Oct 7) |
| Dubuque Rgnl Airport | 1,056 ft | Apr 28 (1 in 10 after May 12) | Oct 11 (before Sep 28) |
| Estherville 4E | 1,320 ft | May 2 (1 in 10 after May 14) | Oct 3 (before Sep 20) |
| Fayette | 1,145 ft | May 4 (1 in 10 after May 17) | Oct 4 (before Sep 20) |
| Forest City 2 Nne | 1,280 ft | Apr 30 (1 in 10 after May 10) | Oct 7 (before Sep 22) |
| Ft Dodge 5NNW | 1,115 ft | Apr 28 (1 in 10 after May 9) | Oct 8 (before Sep 24) |
| Greenfield | 1,316 ft | Apr 25 (1 in 10 after May 7) | Oct 12 (before Sep 26) |
| Grundy Ctr | 985 ft | Apr 29 (1 in 10 after May 12) | Oct 9 (before Sep 25) |
| Guthrie Ctr | 1,065 ft | May 2 (1 in 10 after May 17) | Oct 3 (before Sep 20) |
| Guttenberg L&D 10 | 618 ft | Apr 21 (1 in 10 after May 6) | Oct 18 (before Oct 4) |
| Hampton | 1,105 ft | Apr 29 (1 in 10 after May 10) | Oct 9 (before Sep 26) |
| Indianola 2W | 924 ft | Apr 24 (1 in 10 after May 8) | Oct 12 (before Sep 27) |
| Keokuk Lock Dam 19 | 527 ft | Apr 10 (1 in 10 after Apr 26) | Oct 27 (before Oct 10) |
| Keosauqua | 629 ft | Apr 26 (1 in 10 after May 11) | Oct 13 (before Sep 28) |
| Knoxville | 895 ft | Apr 20 (1 in 10 after May 4) | Oct 19 (before Oct 1) |
| Le Claire L&D 14 | 577 ft | Apr 16 (1 in 10 after Apr 30) | Oct 25 (before Oct 11) |
| Le Mars | 1,195 ft | Apr 30 (1 in 10 after May 12) | Oct 4 (before Sep 21) |
| Manchester #2 | 990 ft | May 3 (1 in 10 after May 16) | Oct 4 (before Sep 22) |
| Mapleton No.2 | 1,200 ft | May 3 (1 in 10 after May 16) | Oct 1 (before Sep 19) |
| Maquoketa | 668 ft | Apr 25 (1 in 10 after May 9) | Oct 14 (before Sep 30) |
| Mason City Muni Airport | 1,225 ft | May 3 (1 in 10 after May 15) | Oct 1 (before Sep 18) |
| Mt Pleasant 1 Ssw | 730 ft | Apr 30 (1 in 10 after May 14) | Oct 10 (before Sep 24) |
| Muscatine | 549 ft | Apr 24 (1 in 10 after May 9) | Oct 14 (before Oct 1) |
| Newton | 960 ft | Apr 22 (1 in 10 after May 4) | Oct 17 (before Oct 1) |
| Osage | 1,170 ft | Apr 30 (1 in 10 after May 12) | Oct 9 (before Sep 25) |
| Ottumwa Industrial Airport | 842 ft | Apr 23 (1 in 10 after May 7) | Oct 14 (before Sep 29) |
| Perry | 950 ft | Apr 25 (1 in 10 after May 8) | Oct 10 (before Sep 25) |
| Pocahontas | 1,212 ft | Apr 26 (1 in 10 after May 8) | Oct 7 (before Sep 25) |
| Rock Rapids | 1,350 ft | May 1 (1 in 10 after May 13) | Oct 4 (before Sep 21) |
| Rockwell City | 1,214 ft | Apr 26 (1 in 10 after May 6) | Oct 10 (before Sep 27) |
| Sac City | 1,210 ft | Apr 30 (1 in 10 after May 11) | Oct 6 (before Sep 23) |
| Sigourney | 732 ft | Apr 24 (1 in 10 after May 9) | Oct 15 (before Sep 30) |
| Sioux City Gateway Airport | 1,095 ft | Apr 29 (1 in 10 after May 14) | Oct 5 (before Sep 22) |
| Sioux Rapids 4 E | 1,420 ft | Apr 30 (1 in 10 after May 11) | Oct 5 (before Sep 22) |
| Vinton | 850 ft | May 3 (1 in 10 after May 17) | Oct 3 (before Sep 20) |
| Washington | 687 ft | Apr 28 (1 in 10 after May 11) | Oct 11 (before Sep 25) |
| Waterloo Muni Airport | 868 ft | Apr 27 (1 in 10 after May 10) | Oct 10 (before Sep 26) |
| Webster City | 1,072 ft | May 3 (1 in 10 after May 16) | Oct 2 (before Sep 18) |
| Williamsburg 1E | 780 ft | Apr 28 (1 in 10 after May 12) | Oct 9 (before Sep 24) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.