Frost dates for Baltimore Wash Intl Airport, MD
At Baltimore Wash Intl Airport, the median last spring frost (32°F) is Apr 10 and the median first fall frost is Oct 31, for a typical growing season of 204 days. For a 90% chance that the last frost has passed, wait until Apr 25. Nearby ZIP codes are in USDA hardiness zones 7b to 8a.
- Apr 10Last spring frost (median)50% chance of 32°F after this date
- Apr 25Safer planting date10% chance of 32°F after this date
- Oct 31First fall frost (median)50% chance of 32°F by this date
- 204 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 9 | Apr 24 | May 12 |
| 32°F | Mar 27 | Apr 10 | Apr 25 |
| 28°F | Mar 13 | Mar 28 | Apr 10 |
| 24°F | Feb 28 | Mar 16 | Mar 31 |
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 8 | Oct 21 | Nov 2 |
| 32°F | Oct 17 | Oct 31 | Nov 12 |
| 28°F | Oct 30 | Nov 10 | Nov 27 |
| 24°F | Nov 8 | Nov 25 | Dec 13 |
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 | 158 days | 179 days | 200 days |
| 32°F | 183 days | 204 days | 223 days |
| 28°F | 208 days | 228 days | 249 days |
| 24°F | 231 days | 254 days | 280 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 |
|---|---|---|---|
| 21240 | 7b | 5 to 10°F | 1 km |
| 21077 | 7b | 5 to 10°F | 2 km |
| 21076 | 7b | 5 to 10°F | 3 km |
| 21061 | 7b | 5 to 10°F | 4 km |
| 21090 | 7b | 5 to 10°F | 5 km |
| 21144 | 7b | 5 to 10°F | 5 km |
| 21075 | 7b | 5 to 10°F | 7 km |
| 21060 | 8a | 10 to 15°F | 9 km |
| 20755 | 7b | 5 to 10°F | 9 km |
| 20794 | 7b | 5 to 10°F | 10 km |
| 20701 | 7b | 5 to 10°F | 10 km |
| 21108 | 7b | 5 to 10°F | 10 km |
| 21113 | 7b | 5 to 10°F | 12 km |
| 21054 | 7b | 5 to 10°F | 12 km |
| 21045 | 7b | 5 to 10°F | 13 km |
| 21043 | 7b | 5 to 10°F | 14 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 USW00093721, at 39.1667, -76.6833, elevation 48 m (156 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 93.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Md Sci Center Baltimore (14 km)
- Laurel 3 W (21 km)
- Cylburn (21 km)
- Glenn Dale Bell Station (24 km)
- Annapolis Police Brks (25 km)
- Beltsville (26 km)
- Annapolis Naf (28 km)
- Upper Marlboro 3 NNW (36 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.