Harman US

Firth, ID Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Firth, a city in Bingham County, Idaho.

Tonight
44°F
Showers And Thunderstorms Likely then Chance Showers And Thunderstorms
Showers and thunderstorms likely before 9pm, then a chance of showers and thunderstorms. Mostly cloudy. Low around 44, with temperatures rising to around 46 overnight. South wind 3 to 8 mph. Chance of precipitation is 70%.

7-day forecast for Firth

WhenTempForecastWindPrecip
Tonight 44°F Showers And Thunderstorms Likely then Chance Showers And Thunderstorms 3 to 8 mph S 70%
Saturday 62°F Chance Showers And Thunderstorms 3 to 7 mph SSW 39%
Saturday Night 43°F Partly Cloudy 3 mph SSE 9%
Sunday 68°F Mostly Sunny 3 mph SSW 0%
Sunday Night 43°F Mostly Clear 3 mph ENE 0%
Monday 75°F Sunny 5 mph NNE 0%
Monday Night 46°F Partly Cloudy 3 mph NE 0%
Tuesday 75°F Mostly Sunny 5 mph N 1%
Tuesday Night 47°F Partly Cloudy 3 mph SSE 5%
Wednesday 76°F Sunny 5 mph SSW 3%
Wednesday Night 46°F Mostly Clear 5 mph SE 3%
Thursday 79°F Sunny 5 mph NNE 2%
Thursday Night 49°F Partly Cloudy 5 mph SE 0%
Friday 79°F Mostly Sunny 7 mph SSE 4%

Forecast source: National Weather Service (api.weather.gov) for Firth (43.306, -112.183). Updated through the day.

Growing snapshot for Firth

Last spring frost
May 5
First fall frost
Oct 3
Growing season
149 days
Hardiness zone
5b

More local growing data for Firth: nearby ZIP 83218 weather · frost dates · planting calendar · Idaho frost dates

Nearby towns & communities

All Idaho locations ›

Climate data from the nearest NOAA station, Blackfoot Fire Dept, Id (12.6 mi from Firth). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.