Signal Mountain, TN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Signal Mountain, a town in Marion County, Tennessee.
Today
66°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy, with a high near 66. South wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.
7-day forecast for Signal Mountain
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 66°F | Showers And Thunderstorms | 5 to 15 mph S | 89% |
| Tonight | 58°F | Showers And Thunderstorms then Mostly Cloudy | 0 to 5 mph W | 95% |
| Thursday | 69°F | Mostly Sunny | 0 to 5 mph W | 0% |
| Thursday Night | 52°F | Mostly Clear | 0 mph | 2% |
| Friday | 68°F | Sunny | 0 to 5 mph N | 2% |
| Friday Night | 48°F | Mostly Clear | 5 mph NW | 1% |
| Saturday | 59°F | Mostly Sunny | 5 to 10 mph N | 0% |
| Saturday Night | 42°F | Partly Cloudy | 5 to 10 mph N | 0% |
| Sunday | 57°F | Mostly Sunny | 5 mph N | 0% |
| Sunday Night | 41°F | Mostly Clear | 5 mph N | 1% |
| Monday | 61°F | Sunny | 5 mph N | 1% |
| Monday Night | 42°F | Mostly Clear | 0 mph | 1% |
| Tuesday | 64°F | Sunny | 0 mph | 2% |
| Tuesday Night | 45°F | Mostly Clear | 0 mph | 2% |
Forecast source: National Weather Service (api.weather.gov) for Signal Mountain (35.144, -85.341). Updated through the day.
Growing snapshot for Signal Mountain
Last spring frost
Mar 31
First fall frost
Nov 6
Growing season
219 days
Hardiness zone
7b
More local growing data for Signal Mountain: nearby ZIP 37405 weather · frost dates · planting calendar · Tennessee frost dates
Nearby towns & communities
Griffith Creek
Jasper
Kimball
Monteagle
New Hope
Powells Crossroads
Sequatchie
South Pittsburg
Whiteside
Whitwell
Climate data from the nearest NOAA station, Lookout Mtn-Point Park, Tn (8.6 mi from Signal Mountain). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.