Signal Mountain, TN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Signal Mountain, a town in Marion County, Tennessee.
This Afternoon
92°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 2pm. Mostly sunny. High near 92, with temperatures falling to around 88 in the afternoon. Heat index values as high as 97. East wind around 0 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Signal Mountain
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 92°F | Chance Showers And Thunderstorms | 0 mph | 35% |
| Tonight | 70°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph E | 40% |
| Sunday | 89°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 to 5 mph S | 30% |
| Sunday Night | 68°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 mph | 28% |
| Monday | 89°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 mph | 44% |
| Monday Night | 68°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 0 mph | 62% |
| Tuesday | 84°F | Showers And Thunderstorms | 0 mph | 81% |
| Tuesday Night | 66°F | Showers And Thunderstorms | 0 to 5 mph E | 81% |
| Wednesday | 78°F | Rain Showers Likely | 0 to 5 mph S | 66% |
| Wednesday Night | 62°F | Showers And Thunderstorms Likely | 0 to 5 mph NE | 66% |
| Thursday | 77°F | Mostly Sunny then Slight Chance Rain Showers | 0 to 5 mph NW | 18% |
| Thursday Night | 60°F | Slight Chance Rain Showers then Partly Cloudy | 0 to 5 mph N | 18% |
| Friday | 77°F | Mostly Sunny | 0 to 5 mph N | 14% |
| Friday Night | 57°F | Partly Cloudy | 5 mph N | 14% |
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 Sep 19, 2026.