Frost dates for National Arboretum DC, MD
At National Arboretum DC, the median last spring frost (32°F) is Mar 29 and the median first fall frost is Nov 8, for a typical growing season of 224 days. For a 90% chance that the last frost has passed, wait until Apr 11. 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 11Safer planting date10% chance of 32°F after this date
- Nov 8First fall frost (median)50% chance of 32°F by this date
- 224 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 29 | Apr 10 | Apr 28 |
| 32°F | Mar 15 | Mar 29 | Apr 11 |
| 28°F | Mar 2 | Mar 17 | Mar 31 |
| 24°F | Feb 17 | Mar 7 | 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 14 | Oct 29 | Nov 10 |
| 32°F | Oct 26 | Nov 8 | Nov 23 |
| 28°F | Nov 6 | Nov 20 | Dec 7 |
| 24°F | Nov 16 | Dec 6 | Dec 28 |
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 | 179 days | 200 days | 219 days |
| 32°F | 205 days | 224 days | 243 days |
| 28°F | 229 days | 248 days | 272 days |
| 24°F | 250 days | 274 days | 300 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 |
|---|---|---|---|
| 20002 | 8a | 10 to 15°F | 1 km |
| 20018 | 7b | 5 to 10°F | 2 km |
| 20722 | 7b | 5 to 10°F | 3 km |
| 20712 | 7b | 5 to 10°F | 3 km |
| 20019 | 8a | 10 to 15°F | 3 km |
| 20017 | 7b | 5 to 10°F | 3 km |
| 20064 | 7b | 5 to 10°F | 4 km |
| 20422 | 7b | 5 to 10°F | 4 km |
| 20510 | 8a | 10 to 15°F | 4 km |
| 20003 | 8a | 10 to 15°F | 4 km |
| 20540 | 8a | 10 to 15°F | 4 km |
| 20001 | 8a | 10 to 15°F | 4 km |
| 20390 | 8a | 10 to 15°F | 4 km |
| 20317 | 7b | 5 to 10°F | 5 km |
| 20781 | 7b | 5 to 10°F | 5 km |
| 20710 | 7b | 5 to 10°F | 5 km |
| 20535 | 8a | 10 to 15°F | 5 km |
| 20005 | 8a | 10 to 15°F | 5 km |
| 20010 | 7b | 5 to 10°F | 6 km |
| 20782 | 7b | 5 to 10°F | 6 km |
| 20009 | 7b | 5 to 10°F | 6 km |
| 20542 | 7b | 5 to 10°F | 6 km |
| 20036 | 8a | 10 to 15°F | 6 km |
| 20011 | 7b | 5 to 10°F | 6 km |
| 20737 | 7b | 5 to 10°F | 7 km |
| 20743 | 7b | 5 to 10°F | 7 km |
| 20785 | 7b | 5 to 10°F | 8 km |
| 20912 | 7b | 5 to 10°F | 8 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 USC00186350, at 38.9133, -76.9700, elevation 15 m (50 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 84.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Dalecarlia Rsvr (13 km)
- Oxon Hill (13 km)
- Beltsville (13 km)
- Glenn Dale Bell Station (16 km)
- Upper Marlboro 3 NNW (19 km)
- Laurel 3 W (20 km)
- Rockville 1 NE (26 km)
- Baltimore Wash Intl Airport (38 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.