Frost dates for Topeka Forbes Field, KS
At Topeka Forbes Field, the median last spring frost (32°F) is Apr 15 and the median first fall frost is Oct 21, for a typical growing season of 185 days. For a 90% chance that the last frost has passed, wait until Apr 30. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 15Last spring frost (median)50% chance of 32°F after this date
- Apr 30Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 185 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 12 | Apr 27 | May 11 |
| 32°F | Apr 2 | Apr 15 | Apr 30 |
| 28°F | Mar 21 | Apr 5 | Apr 21 |
| 24°F | Mar 8 | Mar 27 | Apr 10 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 27 | Oct 11 | Oct 25 |
| 32°F | Oct 5 | Oct 21 | Nov 2 |
| 28°F | Oct 17 | Oct 31 | Nov 12 |
| 24°F | Oct 26 | Nov 8 | Nov 25 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 145 days | 165 days | 184 days |
| 32°F | 164 days | 185 days | 204 days |
| 28°F | 184 days | 205 days | 228 days |
| 24°F | 203 days | 227 days | 250 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 66619 | 6b | -5 to 0°F | 2 km |
| 66609 | 6b | -5 to 0°F | 3 km |
| 66611 | 6b | -5 to 0°F | 8 km |
| 66546 | 6b | -5 to 0°F | 8 km |
| 66409 | 6b | -5 to 0°F | 10 km |
| 66414 | 6b | -5 to 0°F | 13 km |
| 66610 | 6b | -5 to 0°F | 16 km |
| 66402 | 6b | -5 to 0°F | 16 km |
| 66614 | 6b | -5 to 0°F | 16 km |
| 66615 | 6b | -5 to 0°F | 23 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USW00013920, at 38.9503, -95.6639, elevation 325 m (1,067 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 117.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Topeka - NWS (14 km)
- Topeka Muni Airport (14 km)
- Clinton Lake (28 km)
- Perry Lake (29 km)
- Pomona Lake (35 km)
- Lawrence (36 km)
- Osage City (37 km)
- Eskridge (40 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.