Frost dates for Osawatomie, KS
At Osawatomie, the median last spring frost (32°F) is Apr 14 and the median first fall frost is Oct 25, for a typical growing season of 192 days. For a 90% chance that the last frost has passed, wait until Apr 29. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 14Last spring frost (median)50% chance of 32°F after this date
- Apr 29Safer planting date10% chance of 32°F after this date
- Oct 25First fall frost (median)50% chance of 32°F by this date
- 192 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 9 | Apr 23 | May 6 |
| 32°F | Mar 31 | Apr 14 | Apr 29 |
| 28°F | Mar 19 | Apr 3 | Apr 18 |
| 24°F | Mar 8 | Mar 26 | Apr 9 |
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 30 | Oct 15 | Oct 27 |
| 32°F | Oct 11 | Oct 25 | Nov 5 |
| 28°F | Oct 21 | Nov 3 | Nov 18 |
| 24°F | Oct 31 | Nov 11 | Nov 30 |
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 | 153 days | 173 days | 191 days |
| 32°F | 172 days | 192 days | 211 days |
| 28°F | 192 days | 212 days | 232 days |
| 24°F | 210 days | 231 days | 255 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 |
|---|---|---|---|
| 66064 | 6b | -5 to 0°F | 3 km |
| 66042 | 6b | -5 to 0°F | 14 km |
| 66026 | 6b | -5 to 0°F | 14 km |
| 66079 | 6b | -5 to 0°F | 15 km |
| 66072 | 6b | -5 to 0°F | 20 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 USC00146084, at 38.5019, -94.9597, elevation 262 m (860 ft).
- Data quality: Estimated from nearby stations (2+ years), 10 years of freeze data.
- Average days per year at or below 32°F: 114.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Paola (12 km)
- Hillsdale Lake (19 km)
- Ottawa (31 km)
- Garnett 1 E (33 km)
- Olathe Johnson Co Airport (37 km)
- Mound City (42 km)
- Mound City 1ssw (43 km)
- Olathe Johnson Co Exec Airport (43 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.