Boise receives its highest rainfall in Dec, while humidity peaks during winter months.
🌧️ Wettest:Dec — 62 mm☀️ Driest:Jul — 8 mm
💧 Humidity peaks at 82% in Jan · annual avg 56%
🌍 Climate Summary
Avg Annual Temp:52.7°F
Avg Annual Rainfall:409 mm
Avg Humidity:56%
Data Period:1981 – 2025
Boise Climate Overview
Boise has a temperate climate with warm summers and freezing winters.
Temperatures peak in Jul and drop to their lowest in Jan,
while rainfall is highest during winter months.
Humidity remains moderate throughout the year, especially during winter months, creating cold and dry conditions.
📈 Yearly Trends
The warmest year in Boise's recorded history was 2003
(avg: 55.9°F),
while the coldest year was 1982
(avg: 47.8°F),
based on annual average temperatures.
📊 Key Climate Trends
🌡️ Boise's temperature has remained relatively stable over the past decade
📈 Minimum temperatures show a slight warming trend in recent years
🌧️ Rainfall varies year-to-year without a clear long-term trend
🌡️ Annual Temperature Trend
View Range:
Average annual high/low · Last 10 years · °F
Boise's temperatures has remained relatively stable over the past decade.
The highest recorded temperature reached
110.2°F in Jul 2002,
while the lowest dropped to
-14.7°F in Dec 1990.
🌧️ Annual Precipitation
View Range:
Total annual precipitation · Last 10 years · mm/year
Annual rainfall in Boise shows noticeable variation. Rainfall varies year-to-year without a clear long-term trend.
Based on 45 years of data (1981–2025), Jul is typically the hottest month in Boise, Idaho, with average high temperatures around 102.9°F.
What is the coldest month in Boise?▼
Jan is the coldest month in Boise, with average low temperatures around 7.9°F.
What is the rainiest month in Boise?▼
Dec receives the most rainfall with approximately 62 mm, while Jul is the driest with 8 mm.
What was the highest temperature ever recorded in Boise?▼
The highest recorded temperature was 110.2°F in Jul 2002. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Boise?▼
The lowest recorded temperature was -14.7°F in Dec 1990.
How many years of data does this page cover?▼
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
How much sunlight does Boise get?▼
Boise receives the most sunlight in Jul with an average solar radiation of 7.65 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in Idaho.
Where does this weather data come from?▼
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
📚 Data Source
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.