Portland, TN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Portland, a city in Sumner County, Tennessee.
Overnight
65°F
Mostly Clear
Mostly clear, with a low around 65. North northeast wind around 5 mph.
7-day forecast for Portland
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 65°F | Mostly Clear | 5 mph NNE | 0% |
| Tuesday | 87°F | Sunny | 5 mph NE | 3% |
| Tuesday Night | 68°F | Mostly Clear then Patchy Fog | 0 to 5 mph N | 2% |
| Wednesday | 88°F | Patchy Fog then Chance Showers And Thunderstorms | 0 mph | 30% |
| Wednesday Night | 70°F | Partly Cloudy | 0 to 5 mph SSE | 12% |
| Thursday | 90°F | Sunny then Slight Chance Showers And Thunderstorms | 5 mph SSW | 16% |
| Thursday Night | 72°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 mph S | 27% |
| Friday | 90°F | Chance Showers And Thunderstorms | 5 mph SSW | 35% |
| Friday Night | 71°F | Chance Showers And Thunderstorms | 5 mph S | 35% |
| Saturday | 88°F | Chance Showers And Thunderstorms | 5 mph SSW | 45% |
| Saturday Night | 71°F | Chance Showers And Thunderstorms | 0 to 5 mph SSW | 45% |
| Sunday | 89°F | Chance Showers And Thunderstorms | 0 to 5 mph SSW | 34% |
| Sunday Night | 72°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph S | 34% |
| Monday | 90°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 mph SSW | 17% |
Forecast source: National Weather Service (api.weather.gov) for Portland (36.597, -86.527). Updated through the day.
Growing snapshot for Portland
Last spring frost
Apr 5
First fall frost
Nov 1
Growing season
210 days
Hardiness zone
7b
More local growing data for Portland: nearby ZIP 37148 weather · frost dates · planting calendar · Tennessee frost dates
Nearby towns & communities
Bethpage
Bransford
Castalian Springs
Cottontown
Gallatin
Graball
Hendersonville
Mitchellville
New Deal
Oak Grove
Shackle Island
Walnut Grove
Westmoreland
Climate data from the nearest NOAA station, Portland Sewage Plt, Tn (1.7 mi from Portland). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.