San Mar, MD Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for San Mar, a community in Washington County, Maryland.
Tonight
58°F
Isolated Rain Showers then Partly Cloudy
Isolated rain showers before 8pm. Partly cloudy, with a low around 58. Northeast wind around 9 mph. Chance of precipitation is 20%.
7-day forecast for San Mar
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 58°F | Isolated Rain Showers then Partly Cloudy | 9 mph NE | 20% |
| Saturday | 77°F | Partly Sunny | 6 to 9 mph E | 5% |
| Saturday Night | 65°F | Scattered Rain Showers | 9 mph SE | 30% |
| Sunday | 80°F | Showers And Thunderstorms | 9 to 13 mph S | 78% |
| Sunday Night | 63°F | Showers And Thunderstorms | 3 to 9 mph NW | 78% |
| Monday | 70°F | Chance Rain Showers | 8 to 12 mph NE | 40% |
| Monday Night | 59°F | Rain Showers Likely | 7 to 14 mph NE | 58% |
| Tuesday | 62°F | Rain Showers Likely | 10 to 14 mph NE | 73% |
| Tuesday Night | 53°F | Showers And Thunderstorms Likely | 12 to 15 mph NE | 73% |
| Wednesday | 59°F | Rain Showers Likely | 10 to 15 mph NE | 56% |
| Wednesday Night | 53°F | Chance Showers And Thunderstorms | 10 to 14 mph NE | 53% |
| Thursday | 62°F | Chance Showers And Thunderstorms | 8 to 14 mph NE | 51% |
| Thursday Night | 53°F | Chance Rain Showers | 8 mph N | 35% |
| Friday | 67°F | Slight Chance Rain Showers | 9 mph N | 24% |
Forecast source: National Weather Service (api.weather.gov) for San Mar (39.552, -77.641). Updated through the day.
Growing snapshot for San Mar
Last spring frost
Apr 11
First fall frost
Oct 28
Growing season
199 days
Hardiness zone
7a
More local growing data for San Mar: nearby ZIP 21713 weather · frost dates · planting calendar · Maryland frost dates
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Climate data from the nearest NOAA station, Hagerstown 1 E, Md (8.1 mi from San Mar). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.