Frost dates for Lewes, DE
At Lewes, the median last spring frost (32°F) is Mar 29 and the median first fall frost is Nov 14, for a typical growing season of 231 days. For a 90% chance that the last frost has passed, wait until Apr 9. Nearby ZIP codes are in USDA hardiness zones 7b to 8a.
- Mar 29Last spring frost (median)50% chance of 32°F after this date
- Apr 9Safer planting date10% chance of 32°F after this date
- Nov 14First fall frost (median)50% chance of 32°F by this date
- 231 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 | Mar 27 | Apr 9 | Apr 25 |
| 32°F | Mar 13 | Mar 29 | Apr 9 |
| 28°F | Feb 28 | Mar 16 | Mar 30 |
| 24°F | Feb 10 | Mar 4 | Mar 20 |
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 21 | Nov 3 | Nov 16 |
| 32°F | Nov 1 | Nov 14 | Dec 1 |
| 28°F | Nov 9 | Nov 28 | Dec 20 |
| 24°F | Nov 22 | Dec 14 | Jan 5 |
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 | 186 days | 207 days | 225 days |
| 32°F | 213 days | 231 days | 253 days |
| 28°F | 233 days | 256 days | 284 days |
| 24°F | 256 days | 284 days | 310 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 |
|---|---|---|---|
| 19958 | 7b | 5 to 10°F | 6 km |
| 19968 | 7b | 5 to 10°F | 11 km |
| 19971 | 8a | 10 to 15°F | 11 km |
| 19970 | 8a | 10 to 15°F | 26 km |
| 19930 | 8a | 10 to 15°F | 27 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 USC00075320, at 38.7842, -75.1581, elevation 3 m (10 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 59.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Georgetown Sussex Co Airport (20 km)
- Greenwood 2ne (36 km)
- Dover (50 km)
- Wilmington New Castle Co Airport (106 km)
- Newark Ag Farm (111 km)
- Wilmington Porter Rsch (115 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.