Frost dates for Warren, PA
At Warren, the median last spring frost (32°F) is May 4 and the median first fall frost is Oct 21, for a typical growing season of 168 days. For a 90% chance that the last frost has passed, wait until May 22. Nearby ZIP codes are in USDA hardiness zones 5b to 6a.
- May 4Last spring frost (median)50% chance of 32°F after this date
- May 22Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 168 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 30 | May 15 | May 31 |
| 32°F | Apr 20 | May 4 | May 22 |
| 28°F | Apr 8 | Apr 23 | May 11 |
| 24°F | Mar 28 | Apr 9 | Apr 23 |
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 28 | Oct 8 | Oct 22 |
| 32°F | Oct 6 | Oct 21 | Nov 4 |
| 28°F | Oct 18 | Nov 2 | Nov 17 |
| 24°F | Oct 29 | Nov 14 | Dec 1 |
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 | 124 days | 145 days | 165 days |
| 32°F | 147 days | 168 days | 188 days |
| 28°F | 168 days | 192 days | 215 days |
| 24°F | 194 days | 218 days | 241 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 |
|---|---|---|---|
| 16365 | 6a | -10 to -5°F | 1 km |
| 16345 | 6a | -10 to -5°F | 12 km |
| 16352 | 5b | -15 to -10°F | 13 km |
| 16313 | 6a | -10 to -5°F | 15 km |
| 16347 | 5b | -15 to -10°F | 22 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 USC00369298, at 41.8467, -79.1494, elevation 369 m (1,210 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 141.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Chandlers Valley 1se (15 km)
- Kane 1nne (34 km)
- Bradford 4sw Rsch 5 (36 km)
- Bradford Regional Airport (42 km)
- Tionesta 2 SE Lake (48 km)
- Titusville Wtr Wks (51 km)
- Cooksburg 2 NW (55 km)
- Glen Hazel 2 NE Dam (56 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.