Portland, TN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Portland, a city in Sumner County, Tennessee.
Overnight
71°F
Mostly Clear
Mostly clear, with a low around 71. Southeast wind around 0 mph.
7-day forecast for Portland
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 71°F | Mostly Clear | 0 mph | 2% |
| Saturday | 97°F | Patchy Fog then Sunny | 0 to 5 mph WSW | 10% |
| Saturday Night | 72°F | Mostly Clear | 0 to 5 mph S | 4% |
| Sunday | 96°F | Sunny | 5 mph SW | 6% |
| Sunday Night | 71°F | Partly Cloudy | 0 to 5 mph SSW | 4% |
| Monday | 93°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 mph W | 22% |
| Monday Night | 66°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 0 to 5 mph NNE | 51% |
| Tuesday | 84°F | Chance Rain Showers then Chance Showers And Thunderstorms | 5 to 10 mph N | 49% |
| Tuesday Night | 62°F | Chance Showers And Thunderstorms | 5 to 10 mph N | 49% |
| Wednesday | 79°F | Chance Rain Showers | 5 mph NNW | 44% |
| Wednesday Night | 59°F | Slight Chance Rain Showers then Partly Cloudy | 5 mph N | 19% |
| Thursday | 78°F | Mostly Sunny | 5 to 10 mph N | 9% |
| Thursday Night | 58°F | Partly Cloudy | 5 to 10 mph N | 5% |
| Friday | 78°F | Mostly Sunny | 5 to 10 mph NNE | 5% |
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 Sep 19, 2026.