Frost dates for Smithsburg 2nw, MD
At Smithsburg 2nw, the median last spring frost (32°F) is Apr 25 and the median first fall frost is Oct 19, for a typical growing season of 176 days. For a 90% chance that the last frost has passed, wait until May 11. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 25Last spring frost (median)50% chance of 32°F after this date
- May 11Safer planting date10% chance of 32°F after this date
- Oct 19First fall frost (median)50% chance of 32°F by this date
- 176 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 23 | May 5 | May 22 |
| 32°F | Apr 12 | Apr 25 | May 11 |
| 28°F | Mar 30 | Apr 11 | Apr 27 |
| 24°F | Mar 15 | Apr 1 | Apr 14 |
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 | Sep 26 | Oct 8 | Oct 22 |
| 32°F | Oct 6 | Oct 19 | Nov 3 |
| 28°F | Oct 15 | Oct 30 | Nov 14 |
| 24°F | Oct 26 | Nov 10 | Nov 30 |
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 | 134 days | 154 days | 172 days |
| 32°F | 155 days | 176 days | 198 days |
| 28°F | 176 days | 200 days | 220 days |
| 24°F | 202 days | 223 days | 247 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 |
|---|---|---|---|
| 21783 | 7a | 0 to 5°F | 3 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 USC00188371, at 39.6633, -77.5831, elevation 204 m (670 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 122.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Catoctin Mountain Park (9 km)
- Hagerstown 1 E (10 km)
- Hagerstown Washington Co Airport (13 km)
- Emmitsburg 2 SE (26 km)
- Frederick Police Brks (30 km)
- Sharpsburg 5 S (32 km)
- Damascus 3 SSW (54 km)
- Millers 4 NE (67 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.