Frost dates for Royal Oak 2 SSW, MD
At Royal Oak 2 SSW, the median last spring frost (32°F) is Apr 1 and the median first fall frost is Nov 7, for a typical growing season of 220 days. For a 90% chance that the last frost has passed, wait until Apr 15. Nearby ZIP codes are in USDA hardiness zones 7b to 8a.
- Apr 1Last spring frost (median)50% chance of 32°F after this date
- Apr 15Safer planting date10% chance of 32°F after this date
- Nov 7First fall frost (median)50% chance of 32°F by this date
- 220 daysGrowing season (median)between 32°F freezes
USDA hardiness zone 8a (10 to 15°F) · see all zone 8a frost dates
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 31 | Apr 15 | May 3 |
| 32°F | Mar 18 | Apr 1 | Apr 15 |
| 28°F | Mar 3 | Mar 20 | Apr 1 |
| 24°F | Feb 19 | Mar 8 | Mar 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 | Oct 11 | Oct 29 | Nov 10 |
| 32°F | Oct 24 | Nov 7 | Nov 23 |
| 28°F | Nov 5 | Nov 20 | Dec 9 |
| 24°F | Nov 17 | Dec 6 | Dec 27 |
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 | 173 days | 196 days | 216 days |
| 32°F | 202 days | 220 days | 240 days |
| 28°F | 224 days | 246 days | 269 days |
| 24°F | 248 days | 273 days | 299 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 |
|---|---|---|---|
| 21662 | 8a | 10 to 15°F | 1 km |
| 21653 | 8a | 10 to 15°F | 3 km |
| 21654 | 8a | 10 to 15°F | 6 km |
| 21612 | 8a | 10 to 15°F | 8 km |
| 21652 | 8a | 10 to 15°F | 8 km |
| 21663 | 8a | 10 to 15°F | 9 km |
| 21647 | 8a | 10 to 15°F | 12 km |
| 21601 | 8a | 10 to 15°F | 12 km |
| 21676 | 8a | 10 to 15°F | 12 km |
| 21671 | 8a | 10 to 15°F | 13 km |
| 21673 | 8a | 10 to 15°F | 15 km |
| 21624 | 8a | 10 to 15°F | 15 km |
| 21665 | 8a | 10 to 15°F | 16 km |
| 21648 | 8a | 10 to 15°F | 23 km |
| 21655 | 7b | 5 to 10°F | 24 km |
| 21625 | 7b | 5 to 10°F | 25 km |
| 21677 | 8a | 10 to 15°F | 27 km |
| 21657 | 7b | 5 to 10°F | 31 km |
| 21641 | 7b | 5 to 10°F | 31 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 USC00187806, at 38.7153, -76.1908, elevation 3 m (10 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 69.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Stevensville 2SW (31 km)
- Annapolis Naf (38 km)
- Vienna (41 km)
- Annapolis Police Brks (41 km)
- Solomons (50 km)
- Patuxent River NAS (50 km)
- Upper Marlboro 3 NNW (52 km)
- Mechanicsville 5 NE (53 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.