Maryland Frost Dates and Planting Zones
Across 604 ZIP codes we matched to a NOAA weather station, Maryland’s last spring frost (50% risk, 32°F) ranges from May 9 near Sines Deep Creek to Mar 22 near Solomons. First fall frost runs from Oct 9 near Oakland 1 se to Nov 26 near Solomons. Look up your exact ZIP code on the frost date tool for a station-matched result and hardiness zone.
Frost dates by city in Maryland
The 12 weather stations covering the most MD ZIP codes, at the 50% and 10% probability levels (32°F threshold). The 10% date is later and safer to plant after; the 50% date is the typical planning date.
| Station | Last frost (50%) | Last frost (10%) | First frost (50%) | First frost (10%) |
|---|---|---|---|---|
| Rockville 1 ne | Apr 1 | Apr 15 | Nov 6 | Oct 24 |
| Cylburn | Apr 2 | Apr 13 | Nov 7 | Oct 27 |
| md Sci Ctr Baltimore | Mar 24 | Apr 4 | Nov 21 | Nov 7 |
| Mechanicsville 5 ne | Apr 17 | May 2 | Oct 27 | Oct 12 |
| Glenn Dale Bell Stn | Apr 22 | May 9 | Oct 22 | Oct 7 |
| Frederick Police Brks | Apr 2 | Apr 15 | Nov 6 | Oct 23 |
| Baltimore Wash Intl ap | Apr 10 | Apr 25 | Oct 31 | Oct 17 |
| Royal Oak 2 Ssw | Apr 1 | Apr 15 | Nov 7 | Oct 24 |
| Damascus 3 Ssw | Apr 14 | May 2 | Oct 29 | Oct 13 |
| Laurel 3 w | Apr 5 | Apr 19 | Nov 9 | Oct 27 |
| Aberdeen Phillips Fld | Apr 10 | Apr 30 | Oct 30 | Oct 14 |
| Savage Rvr Dam | Apr 29 | May 15 | Oct 20 | Oct 4 |
USDA hardiness zones in Maryland
Share of Maryland ZIP codes in each 2023 USDA Plant Hardiness Zone. 75% of MD ZIP codes moved to a different zone between the 2012 and 2023 maps, mostly warming as winter lows trended up.
| Zone (2023) | Share of MD ZIPs |
|---|---|
| 6a | 1.5% |
| 6b | 1.2% |
| 7a | 16.4% |
| 7b | 61.2% |
| 8a | 19.7% |
Climate is shifting
Averaged across MD stations with both normals periods, the last spring frost now lands about 2 days earlier than the 1981–2010 normal. First fall frost now lands about 3 days later, stretching or shrinking the frost-free season depending on the station.
Plan around your Maryland frost dates
Once you know your local last and first frost, these guides help you time the work around them: