Boise, United States experiences average highs of 19°C (66°F) and lows of 7°C (45°F) throughout the year. The climate is relatively dry, with only 6 rainy days per month on average. Sunshine is abundant, averaging about 10 hours per day. Average highs have stayed broadly stable across the available records.
Boise, United States Weather & Climate 2026
Monthly climate averages for Boise, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Apr–Nov 
Wetter season: Jan–Dec At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
6.1/10
Best: June, July, August, September
UV Index
5
Low
Temperature 19°C / 7°C
Feels Like 16°C / 4°C
Rainy Days 6
Rainfall 28 mm
Sunshine 10 h
Humidity 54%
Wind Speed 18 km/h
Dew Point 3°C
Snow Days 5 days
Frost Days 14 days
Hottest Month
35°C
July
Avg Low19°C
Rain1days
Coldest Month
-4°C
January
Avg High4°C
Rain10days
Driest Month
1days
July
Avg High35°C
Avg Low19°C
Windiest Month
21 km/h
April (Gusts 42)
Worst Time to Visit
Consider avoiding January, February, December due to very cold temperatures.
Sun Position
Sunrise 06:04
Daylight 15.4h
Sunset 21:29
Live conditions—
Boise on the map · live conditions
Boise, United States
- Continent
- Americas
- Country
- United States
- City
- Boise
- Population
- 235.7K
- Elevation
- 823 m
- Coordinates
- 43.61°, -116.20°
Seasonal Breakdown
Spring
Mar–May
Avg High 18°C
Avg Low 5°C
Rain 8 days/mo
Summer
Jun–Aug
Avg High 32°C
Avg Low 17°C
Rain 2 days/mo
3/3 best months
Autumn
Sep–Nov
Avg High 19°C
Avg Low 7°C
Rain 4 days/mo
1/3 best months
Winter
Dec–Feb
Avg High 5°C
Avg Low -3°C
Rain 10 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 4°C / -4°C . Feb: 7°C / -2°C . Mar: 13°C / 1°C . Apr: 18°C / 4°C . May: 23°C / 9°C . Jun: 29°C / 14°C . Jul: 35°C / 19°C . Aug: 33°C / 18°C . Sep: 28°C / 14°C . Oct: 19°C / 7°C . Nov: 11°C / 2°C . Dec: 5°C / -3°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 46 mm. Feb: 41 mm. Mar: 40 mm. Apr: 31 mm. May: 34 mm. Jun: 16 mm. Jul: 2 mm. Aug: 8 mm. Sep: 9 mm. Oct: 26 mm. Nov: 30 mm. Dec: 51 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 75%. Feb: 69%. Mar: 63%. Apr: 54%. May: 51%. Jun: 41%. Jul: 29%. Aug: 33%. Sep: 41%. Oct: 54%. Nov: 67%. Dec: 75%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 18 km/h . Feb: 20 km/h . Mar: 20 km/h . Apr: 21 km/h . May: 20 km/h . Jun: 19 km/h . Jul: 17 km/h . Aug: 17 km/h . Sep: 17 km/h . Oct: 18 km/h . Nov: 17 km/h . Dec: 17 km/h .
Sunshine
Sunshine
Sunshine: Jan: 7h. Feb: 8h. Mar: 9h. Apr: 11h. May: 12h. Jun: 13h. Jul: 14h. Aug: 13h. Sep: 11h. Oct: 9h. Nov: 7h. Dec: 6h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 2. Feb: UV 3. Mar: UV 5. Apr: UV 6. May: UV 7. Jun: UV 8. Jul: UV 8. Aug: UV 7. Sep: UV 6. Oct: UV 4. Nov: UV 3. Dec: UV 2.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 8 days. Feb: 8 days. Mar: 4 days. Apr: 1 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 2 days. Dec: 8 days.
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall has remained broadly steady.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 34°C | Jul · 35°C |
| Coldest month | Jan 2025 · -4°C | Jan · -4°C |
| Wettest month | Feb 2025 · 85 mm | Dec · 51 mm |
| Windiest month | Mar 2025 · 21 km/h | Apr · 21 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Fair April
Fair May
Good June best
Excellent July best
Excellent August best
Excellent September best
Excellent October
Good November
Poor December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 4°C / -4°C | 1°C / -8°C | 10days (46 mm) Wet | 6.5h Fair | 75% Muggy | 2.2 Moderate | Poor | View Details |
| February | 7°C / -2°C | 3°C / -6°C | 9days (41 mm) Wet | 7.5h Good | 69% Muggy | 3.1 Moderate | Poor | View Details |
| March | 13°C / 1°C | 9°C / -3°C | 10days (40 mm) Wet | 9.4h Good | 63% Muggy | 4.7 Moderate | Fair | View Details |
| April | 18°C / 4°C | 14°C / 1°C | 6days (31 mm) Good | 11h Excellent | 54% Moderate | 6.3 High | Fair | View Details |
| May | 23°C / 9°C | 21°C / 6°C | 7days (34 mm) Good | 12.4h Excellent | 51% Moderate | 7.2 Very High | Good | View Details |
| June best | 29°C / 14°C | 27°C / 12°C | 3days (16 mm) Excellent | 13.4h Excellent | 41% Moderate | 7.7 Very High | Excellent | View Details |
| July best | 35°C / 19°C | 33°C / 18°C | 1days (2 mm) Excellent | 13.8h Excellent | 29% Comfortable | 7.8 Very High | Excellent | View Details |
| August best | 33°C / 18°C | 32°C / 17°C | 1days (8 mm) Excellent | 12.5h Excellent | 33% Comfortable | 7 High | Excellent | View Details |
| September best | 28°C / 14°C | 25°C / 12°C | 2days (9 mm) Excellent | 11h Excellent | 41% Moderate | 5.8 High | Excellent | View Details |
| October | 19°C / 7°C | 15°C / 4°C | 5days (26 mm) Good | 9h Good | 54% Moderate | 4.2 Moderate | Good | View Details |
| November | 11°C / 2°C | 7°C / -2°C | 6days (30 mm) Good | 7.2h Good | 67% Muggy | 2.5 Moderate | Poor | View Details |
| December | 5°C / -3°C | 1°C / -7°C | 10days (51 mm) Wet | 5.8h Fair | 75% Muggy | 1.8 Low | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Boise are June, July, August, September, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Boise, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Boise is July, with average daytime highs of 35°C (94°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Boise is January, with average overnight lows of -4°C (25°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Boise is December, averaging 51mm of precipitation across 10 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Boise runs through January, March, December, with the heaviest rainfall in January. Based on 10-year averages for Boise.
Boise receives approximately 120 sunshine hours per year. The sunniest month is July with around 14 hours. Based on climate data for Boise.
The least favorable months to visit Boise are January, February, December, primarily due to very cold temperatures. For the best conditions, consider June, July, August, September instead.
The annual average UV index in Boise is 5, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Boise is 54%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes, Boise receives snow. Months with snowfall average 5 snow days and 7 cm (3 in) of accumulation, with about 14 frost days during winter.
Average wind speeds in Boise are 18 km/h (11 mph). The windiest month is April with peak winds reaching 21 km/h (13 mph) (gusts up to 42 km/h / 26 mph).
Boise averages 9 clear-sky days per month with overall cloud cover around 45%. The clearest skies occur in July.
The annual average dew point in Boise is 3°C (37°F), which feels dry and comfortable. Outdoor activities are comfortable year-round from a humidity standpoint.
Boise has a Hot-Summer Mediterranean climate, classified as Csa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Boise ranges from 4°C (39°F) to 16°C (61°F) on average. Wind chill makes winters feel noticeably colder than the actual temperature — layered clothing is recommended.
Yes, June is a great time to visit Boise. It earns a climate score of 9.8/10 with Excellent.
For June in Boise, pack Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses, Sandals. With average highs of 29°C (84°F) and 3 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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