Frost dates for Wamego 4 W, KS
At Wamego 4 W, the median last spring frost (32°F) is Apr 18 and the median first fall frost is Oct 19, for a typical growing season of 183 days. For a 90% chance that the last frost has passed, wait until May 2. Nearby ZIP codes are in USDA hardiness zones 6a to 6b.
- Apr 18Last spring frost (median)50% chance of 32°F after this date
- May 2Safer planting date10% chance of 32°F after this date
- Oct 19First fall frost (median)50% chance of 32°F by this date
- 183 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 13 | Apr 28 | May 10 |
| 32°F | Apr 4 | Apr 18 | May 2 |
| 28°F | Mar 25 | Apr 8 | Apr 23 |
| 24°F | Mar 13 | Mar 31 | Apr 14 |
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 26 | Oct 10 | Oct 22 |
| 32°F | Oct 3 | Oct 19 | Nov 1 |
| 28°F | Oct 14 | Oct 28 | Nov 10 |
| 24°F | Oct 23 | Nov 5 | Nov 24 |
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 | 164 days | 184 days |
| 32°F | 163 days | 183 days | 202 days |
| 28°F | 182 days | 203 days | 223 days |
| 24°F | 199 days | 222 days | 245 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 |
|---|---|---|---|
| 66547 | 6b | -5 to 0°F | 7 km |
| 66535 | 6a | -10 to -5°F | 8 km |
| 66407 | 6b | -5 to 0°F | 16 km |
| 66501 | 6b | -5 to 0°F | 21 km |
| 66549 | 6a | -10 to -5°F | 24 km |
| 66536 | 6b | -5 to 0°F | 26 km |
| 66422 | 6a | -10 to -5°F | 28 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 USC00148563, at 39.2142, -96.3700, elevation 355 m (1,166 ft).
- Data quality: Representative (10+ years), 24 years of freeze data.
- Average days per year at or below 32°F: 119.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Manhattan (18 km)
- Tuttle Creek Lake (20 km)
- Manhattan 6 SSW (24 km)
- Manhattan Muni Airport (28 km)
- Eskridge (46 km)
- Milford Lake (48 km)
- Holton (59 km)
- Centralia (60 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.