Frost dates for Mechanicsville 5 NE, MD
At Mechanicsville 5 NE, the median last spring frost (32°F) is Apr 17 and the median first fall frost is Oct 27, for a typical growing season of 195 days. For a 90% chance that the last frost has passed, wait until May 2. Nearby ZIP codes are in USDA hardiness zones 7b to 8a.
- Apr 17Last spring frost (median)50% chance of 32°F after this date
- May 2Safer planting date10% chance of 32°F after this date
- Oct 27First fall frost (median)50% chance of 32°F by this date
- 195 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 15 | Apr 30 | May 15 |
| 32°F | Mar 31 | Apr 17 | May 2 |
| 28°F | Mar 19 | Apr 2 | Apr 17 |
| 24°F | Mar 2 | Mar 21 | Apr 4 |
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 3 | Oct 16 | Oct 31 |
| 32°F | Oct 12 | Oct 27 | Nov 9 |
| 28°F | Oct 24 | Nov 6 | Nov 23 |
| 24°F | Nov 3 | Nov 20 | Dec 8 |
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 | 149 days | 170 days | 192 days |
| 32°F | 173 days | 195 days | 215 days |
| 28°F | 198 days | 219 days | 242 days |
| 24°F | 219 days | 244 days | 269 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 |
|---|---|---|---|
| 20612 | 7b | 5 to 10°F | 4 km |
| 20637 | 7b | 5 to 10°F | 4 km |
| 20659 | 7b | 5 to 10°F | 9 km |
| 20608 | 7b | 5 to 10°F | 10 km |
| 20678 | 7b | 5 to 10°F | 12 km |
| 20617 | 7b | 5 to 10°F | 12 km |
| 20660 | 7b | 5 to 10°F | 14 km |
| 20622 | 7b | 5 to 10°F | 16 km |
| 20676 | 7b | 5 to 10°F | 16 km |
| 20639 | 7b | 5 to 10°F | 16 km |
| 20624 | 7b | 5 to 10°F | 17 km |
| 20656 | 7b | 5 to 10°F | 18 km |
| 20602 | 7b | 5 to 10°F | 18 km |
| 20601 | 7b | 5 to 10°F | 18 km |
| 20621 | 7b | 5 to 10°F | 20 km |
| 20632 | 7b | 5 to 10°F | 21 km |
| 20611 | 7b | 5 to 10°F | 23 km |
| 20664 | 7b | 5 to 10°F | 23 km |
| 20689 | 7b | 5 to 10°F | 23 km |
| 20609 | 8a | 10 to 15°F | 24 km |
| 20646 | 7b | 5 to 10°F | 24 km |
| 20732 | 8a | 10 to 15°F | 24 km |
| 20618 | 8a | 10 to 15°F | 25 km |
| 20606 | 8a | 10 to 15°F | 26 km |
| 20645 | 7b | 5 to 10°F | 27 km |
| 20661 | 7b | 5 to 10°F | 28 km |
| 20625 | 8a | 10 to 15°F | 28 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 USC00185865, at 38.4928, -76.7258, elevation 30 m (100 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 98.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Solomons (31 km)
- Patuxent River NAS (34 km)
- Upper Marlboro 3 NNW (40 km)
- Oxon Hill (41 km)
- St. Inigoes Webster Nolf (47 km)
- National Arboretum DC (51 km)
- Royal Oak 2 SSW (53 km)
- Glenn Dale Bell Station (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.