Frost dates for Wilmington Porter Rsch, DE
At Wilmington Porter Rsch, the median last spring frost (32°F) is Apr 7 and the median first fall frost is Nov 4, for a typical growing season of 209 days. For a 90% chance that the last frost has passed, wait until Apr 24. Nearby ZIP codes are in USDA hardiness zones 7a to 7b.
- Apr 7Last spring frost (median)50% chance of 32°F after this date
- Apr 24Safer planting date10% chance of 32°F after this date
- Nov 4First fall frost (median)50% chance of 32°F by this date
- 209 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 6 | Apr 20 | May 7 |
| 32°F | Mar 26 | Apr 7 | Apr 24 |
| 28°F | Mar 13 | Mar 29 | Apr 10 |
| 24°F | Mar 1 | Mar 17 | Mar 31 |
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 | Oct 9 | Oct 24 | Nov 6 |
| 32°F | Oct 21 | Nov 4 | Nov 19 |
| 28°F | Nov 1 | Nov 15 | Dec 2 |
| 24°F | Nov 11 | Nov 28 | Dec 16 |
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 | 165 days | 185 days | 204 days |
| 32°F | 189 days | 209 days | 229 days |
| 28°F | 213 days | 232 days | 254 days |
| 24°F | 232 days | 254 days | 278 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 |
|---|---|---|---|
| 19806 | 7b | 5 to 10°F | 2 km |
| 19802 | 7b | 5 to 10°F | 2 km |
| 19803 | 7b | 5 to 10°F | 3 km |
| 19809 | 7b | 5 to 10°F | 4 km |
| 19732 | 7b | 5 to 10°F | 4 km |
| 19710 | 7b | 5 to 10°F | 4 km |
| 19805 | 7b | 5 to 10°F | 5 km |
| 19801 | 7b | 5 to 10°F | 6 km |
| 19810 | 7b | 5 to 10°F | 6 km |
| 19735 | 7b | 5 to 10°F | 6 km |
| 19807 | 7b | 5 to 10°F | 7 km |
| 08069 | 7b | 5 to 10°F | 11 km |
| 19317 | 7a | 0 to 5°F | 11 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 USC00079605, at 39.7739, -75.5414, elevation 82 m (270 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 87.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Wilmington New Castle Co Airport (12 km)
- Newark Ag Farm (21 km)
- Dover (70 km)
- Greenwood 2ne (107 km)
- Lewes (115 km)
- Georgetown Sussex Co Airport (122 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.