Ada County Climate
Ada County, Idaho
Avg Annual Temp
52.8°F
Annual Precip
13.1"
Annual Snowfall
37.5"
Extreme Heat Days
53.35
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Seasonal Overview
National Comparison
Climate Profile
About Ada County Weather
Ada County matches national temperature averages
The county's average annual temperature of 52.8°F aligns almost perfectly with the national median. This creates a semi-arid climate that balances high-desert warmth with distinct seasonal shifts.
Idaho's warmest pocket of activity
Ada County is significantly warmer than the Idaho average of 46.5°F, making it one of the state's mildest regions. This warmth supports the capital's growth but brings more intense summer heat than most of the state.
Warmer and drier than mountain neighbors
With only 13.1 inches of annual precipitation, Ada is much drier than neighboring Boise County. It averages nearly 8 degrees warmer than its northern neighbors, serving as the Treasure Valley's heat center.
Hot summers and manageable winters
Residents face 53 days of extreme heat above 90°F, far exceeding the state norm. Winters remain relatively mild with an average January temperature of 32.3°F and a modest 37.5 inches of snowfall.
Prioritize cooling and summer hydration
Investing in high-efficiency HVAC systems is essential to handle the two months of frequent 90-degree days. Water-wise landscaping helps residents maintain properties during the dry 13.1-inch annual rainfall cycle.
Frequently Asked Questions
What is the average temperature in Ada County?
How much rain does Ada County get?
Does it snow in Ada County?
How hot does Ada County get in summer?
How cold are winters in Ada County?
Track your own weather in Ada County
Ambient Weather personal weather stations give you hyperlocal climate data.
Sponsored
Data source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.
Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.