Lost River, ID Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lost River, a city in Butte County, Idaho.
This Afternoon
59°F
Scattered Showers And Thunderstorms
Scattered showers and thunderstorms. Mostly cloudy, with a high near 59. East southeast wind around 6 mph. Chance of precipitation is 50%.
7-day forecast for Lost River
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 59°F | Scattered Showers And Thunderstorms | 6 mph ESE | 46% |
| Tonight | 37°F | Isolated Rain Showers then Partly Cloudy | 1 to 5 mph N | 17% |
| Sunday | 66°F | Sunny | 2 to 8 mph SSE | 3% |
| Sunday Night | 40°F | Mostly Clear | 5 mph WNW | 1% |
| Monday | 70°F | Sunny | 1 to 9 mph ENE | 1% |
| Monday Night | 43°F | Partly Cloudy | 2 to 8 mph W | 0% |
| Tuesday | 72°F | Mostly Sunny | 1 to 10 mph NNE | 2% |
| Tuesday Night | 44°F | Mostly Cloudy | 1 to 8 mph W | 12% |
| Wednesday | 72°F | Sunny | 1 to 12 mph WSW | 8% |
| Wednesday Night | 44°F | Partly Cloudy | 2 to 9 mph WSW | 4% |
| Thursday | 75°F | Sunny | 1 to 13 mph SW | 1% |
| Thursday Night | 45°F | Partly Cloudy | 1 to 10 mph SW | 1% |
| Friday | 75°F | Mostly Sunny | 2 to 13 mph SE | 3% |
| Friday Night | 44°F | Partly Cloudy | 2 to 12 mph WSW | 8% |
Forecast source: National Weather Service (api.weather.gov) for Lost River (43.688, -113.635). Updated through the day.
Growing snapshot for Lost River
Last spring frost
May 22
First fall frost
Sep 22
Growing season
119 days
Hardiness zone
5a
More local growing data for Lost River: nearby ZIP 83255 weather · frost dates · planting calendar · Idaho frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Arco, Id (9.6 mi from Lost River). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.