Firth, ID Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Firth, a city in Bingham County, Idaho.
Tonight
31°F
Patchy Fog
Patchy fog after 8pm. Mostly cloudy. Low around 31, with temperatures rising to around 34 overnight. Northeast wind 2 to 6 mph.
7-day forecast for Firth
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 31°F | Patchy Fog | 2 to 6 mph NE | 1% |
| Wednesday | 49°F | Patchy Fog then Partly Sunny | 2 to 7 mph W | 1% |
| Wednesday Night | 28°F | Areas Of Fog | 5 mph SSE | 0% |
| Thursday | 48°F | Areas Of Fog then Partly Sunny | 5 mph S | 6% |
| Thursday Night | 29°F | Areas Of Fog | 5 mph SSW | 6% |
| Friday | 48°F | Mostly Sunny | 5 mph SW | 1% |
| Friday Night | 29°F | Partly Cloudy | 3 mph SE | 1% |
| Saturday | 51°F | Sunny | 1 to 5 mph NNE | 0% |
| Saturday Night | 30°F | Partly Cloudy | 3 mph ENE | 0% |
| Sunday | 57°F | Mostly Sunny | 5 mph S | 0% |
| Sunday Night | 33°F | Partly Cloudy | 3 mph SSE | 0% |
| Monday | 56°F | Partly Sunny | 3 mph NNE | 0% |
| Monday Night | 34°F | Mostly Cloudy | 3 mph SSE | 2% |
| Tuesday | 56°F | Mostly Sunny | 5 mph SSW | 6% |
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
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 Nov 4, 2026.