Lemhi County Climate
Lemhi County, Idaho
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
43.2°F
Annual Precip
9.0"
Annual Snowfall
22.0"
Extreme Heat Days
24
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
5b
Minimum winter temperature range for plant survival
1,675
Favors cool-season crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Lemhi County
Climate Verdict
Lemhi County has a cool, averaging 43.2°F annually, arid conditions receiving just 9.0 inches of precipitation annually, occasional hot days — 24.339999999999996 per year above 90°F, moderate snowfall of 22.0 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 20.0°F. summers are pleasantly cool with July averaging 66.8°F. The 47°F seasonal variation provides noticeable but manageable change.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Lemhi County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Lemhi County is 3.4°F cooler than the Idaho statewide average of 46.5°F, it is also noticeably drier, receiving 8.0 inches less precipitation than the state average.
Climate Profile
About Lemhi County Weather
A cold and arid mountain retreat
Lemhi County is one of the colder spots in the country, with an annual average temperature of just 43.2°F. It is extremely dry, receiving only 9.0 inches of annual precipitation.
Much colder than the state average
The county's 43.2°F average is over three degrees colder than the Idaho state average of 46.5°F. It is also one of the driest counties in the state, falling 8 inches below the state's 17-inch precipitation average.
Colder than Jefferson and Idaho counties
Lemhi County is notably colder than Jefferson and Idaho counties, which both average 44.8°F. It also receives the least precipitation among its regional peers, totaling only 9 inches annually.
Harsh winters and sharp summer spikes
January is frigid with an average of 20.0°F and 22 inches of annual snowfall. Despite the cold year-round average, the county still experiences 24 days above 90°F during the dry summer months.
Prepare for the deep freeze
Heavy-duty home insulation and reliable heating sources are critical to surviving the 20°F January average. Residents should also plan for dry conditions by utilizing moisture-retaining landscaping to manage the low rainfall.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.