Decatur, TN Weather & Growing Conditions
Today
89°F
Mostly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after noon. Mostly sunny. High near 89, with temperatures falling to around 86 in the afternoon. Heat index values as high as 98. Northeast wind around 0 mph. Chance of precipitation is 30%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 89°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 mph | 32% |
| Tonight | 69°F | Chance Showers And Thunderstorms then Mostly Cloudy | 0 mph | 28% |
| Wednesday | 87°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 to 5 mph S | 53% |
| Wednesday Night | 69°F | Chance Showers And Thunderstorms | 0 mph | 51% |
| Thursday | 88°F | Chance Showers And Thunderstorms | 0 to 5 mph S | 50% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 mph | 50% |
| Friday | 89°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 to 5 mph S | 38% |
| Friday Night | 69°F | Chance Showers And Thunderstorms | 0 mph | 38% |
| Saturday | 89°F | Showers And Thunderstorms Likely | 0 mph | 57% |
| Saturday Night | 70°F | Showers And Thunderstorms Likely | 0 mph | 57% |
| Sunday | 89°F | Chance Showers And Thunderstorms | 0 mph | 38% |
| Sunday Night | 71°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 mph | 38% |
| Monday | 90°F | Chance Showers And Thunderstorms | 0 mph | 43% |
| Monday Night | 72°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 mph | 43% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Decatur, TN
Last spring frost
Apr 4
First fall frost
Oct 31
Growing season
208 days
Hardiness zone
7b
Explore more for Decatur, TN: full frost dates · planting calendar · Tennessee frost dates
Climate data from the nearest NOAA station, Dayton 2Se, Tn (9.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.