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Firth, ID Weather & Growing Conditions

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

Overnight
44°F
Slight Chance Light Rain
A slight chance of rain after 3am. Mostly cloudy. Low around 44, with temperatures rising to around 46 overnight. South southwest wind around 5 mph. Chance of precipitation is 20%.

7-day forecast for Firth

WhenTempForecastWindPrecip
Overnight 44°F Slight Chance Light Rain 5 mph SSW 22%
Saturday 62°F Chance Light Rain then Slight Chance Showers And Thunderstorms 3 to 7 mph SSW 29%
Saturday Night 39°F Partly Cloudy 0 to 5 mph SSE 8%
Sunday 69°F Mostly Sunny 3 mph W 1%
Sunday Night 40°F Mostly Clear 3 mph ENE 0%
Monday 74°F Sunny 5 mph NNE 0%
Monday Night 43°F Mostly Clear 3 mph ENE 0%
Tuesday 76°F Mostly Sunny 6 mph NNE 1%
Tuesday Night 46°F Partly Cloudy 3 mph ESE 13%
Wednesday 76°F Mostly Sunny 5 mph SSE 8%
Wednesday Night 45°F Mostly Clear 5 mph SE 4%
Thursday 79°F Sunny 6 mph SSE 2%
Thursday Night 47°F Partly Cloudy 6 mph SE 3%
Friday 80°F Mostly Sunny 8 mph SSE 1%

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

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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.