Frost dates for Patuxent River NAS, MD
At Patuxent River NAS, the median last spring frost (32°F) is Mar 29 and the median first fall frost is Nov 15, for a typical growing season of 230 days. For a 90% chance that the last frost has passed, wait until Apr 10. Nearby ZIP codes are in USDA hardiness zone 8a.
- Mar 29Last spring frost (median)50% chance of 32°F after this date
- Apr 10Safer planting date10% chance of 32°F after this date
- Nov 15First fall frost (median)50% chance of 32°F by this date
- 230 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 28 | Apr 9 | Apr 24 |
| 32°F | Mar 15 | Mar 29 | Apr 10 |
| 28°F | Feb 28 | Mar 18 | Apr 1 |
| 24°F | Feb 14 | Mar 6 | Mar 22 |
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 2 | Nov 16 |
| 32°F | Nov 1 | Nov 15 | Dec 1 |
| 28°F | Nov 10 | Nov 29 | Dec 18 |
| 24°F | Nov 25 | Dec 13 | Jan 3 |
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 | 226 days |
| 32°F | 210 days | 230 days | 251 days |
| 28°F | 231 days | 254 days | 278 days |
| 24°F | 257 days | 282 days | 306 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 |
|---|---|---|---|
| 20670 | 8a | 10 to 15°F | 2 km |
| 20653 | 8a | 10 to 15°F | 7 km |
| 21634 | 8a | 10 to 15°F | 19 km |
| 21669 | 8a | 10 to 15°F | 21 km |
| 21622 | 8a | 10 to 15°F | 26 km |
| 21675 | 8a | 10 to 15°F | 29 km |
| 21627 | 8a | 10 to 15°F | 33 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 USW00013721, at 38.3000, -76.4167, elevation 12 m (39 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 68.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Solomons (4 km)
- St. Inigoes Webster Nolf (18 km)
- Mechanicsville 5 NE (34 km)
- Royal Oak 2 SSW (50 km)
- Vienna (56 km)
- Upper Marlboro 3 NNW (69 km)
- Salisbury (73 km)
- Salisbury 2n (73 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.