Boise in August

In August, Boise averages 34°C (92°F) during the day and 18°C (64°F) at night, with only about 1 rainy day.

Shoulder

Conditions are very hot — early-morning and evening sightseeing recommended. Skies are generally dry and clear.

It's peak hurricane season in Boise during August. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

34°C
Avg high
18°C
Avg low
1
Rain days
5 mm
Rainfall

How August compares to the rest of the year in Boise

2nd
warmest month of the 12
12th
wettest month of the 12
1%
of yearly rainfall falls in August
14 h 0 min
daylight on the 15th

August is one of the warmest months in Boise (2nd of 12) and one of the driest months (12th of 12). Daytime temperature runs 15°C above the annual average (19°C). August runs 1°C cooler than July (35°C) and cools 6°C in September (28°C).

August sunrise & sunset in Boise

🌅
Sunrise (15th)
6:49 AM
🌇
Sunset (15th)
8:49 PM
Day length
14 h 0 min

Times shown for Boise local time (America/Boise), calculated for the 15th of August. They shift by a few minutes day to day across the month.

Photography light in Boise — August

Golden-hour and blue-hour windows for the 15th of August, in Boise's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
5:49 AM – 6:29 AM
🌄 Golden hour (AM)
6:29 AM – 7:29 AM
🌇 Golden hour (PM)
8:09 PM – 9:09 PM
🌆 Blue hour (PM)
9:09 PM – 9:49 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Boise.

📅 When to book — Boise in August

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on August's tier (Shoulder) and Boise's popularity.

✈ Flights — lead time
6-10 weeks
Sweet spot for value. Major fare-sales (US: Black Friday, EU: post-Easter) hit hardest in shoulder months for shoulder travel. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
4-8 weeks
Lots of selection. Look for shoulder-season packages — many hotels add value (free breakfast, spa credit) to fill rooms.

Crowds & pricing — August in Boise

Shoulder

Boise is in a shoulder season month — fewer crowds, slightly lower prices, and a calmer atmosphere than peak weeks. Most major sights stay open with normal hours, though a handful of seasonal restaurants or boat trips may run reduced schedules. Many regulars consider these months the best time to visit because you trade a small amount of weather reliability for a much more pleasant on-the-ground experience.

Why this tier: Northern Hemisphere summer holidays peak hazard season (1 active)

Sun & mosquito risk — August in Boise

☀️ UV Index (noon, 15th)
10.8
Very high
Limit sun exposure between 11 AM and 3 PM; SPF 30-50, reapply every 90 minutes outdoors.
🦟 Mosquito risk
●●●○○
Moderate
Active mosquito season. DEET 25-30% repellent recommended, especially at dawn/dusk.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Boise in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 4°C / 40°F -4°C / 26°F 43 mm 10
February 8°C / 46°F -2°C / 29°F 38 mm 9
March 13°C / 56°F 2°C / 35°F 39 mm 9
April 18°C / 64°F 4°C / 40°F 31 mm 7
May 23°C / 74°F 9°C / 48°F 39 mm 8
June 29°C / 84°F 14°C / 57°F 22 mm 3
July 35°C / 95°F 19°C / 65°F 2 mm 1
August 34°C / 92°F 18°C / 64°F 5 mm 1
September 28°C / 82°F 13°C / 55°F 15 mm 3
October 19°C / 66°F 7°C / 44°F 26 mm 5
November 10°C / 50°F 0°C / 33°F 37 mm 8
December 4°C / 39°F -3°C / 26°F 55 mm 12

Other cities with similar August weather

🌍 See the full ranked list of climate twins for Boise in August →

Frequently asked questions

How hot is Boise in August?

In August, Boise averages a high of 34°C (92°F) and a low of 18°C (64°F) — generally hot.

Does it rain a lot in Boise in August?

August is generally dry in Boise, with about 1 rainy day on average.

Is August a good time to visit Boise?

August is hot and mostly dry. It suits travelers who are comfortable with hot weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Boise in August?

Pack lightweight, breathable clothing, sunglasses and sunscreen. See the full August packing list for Boise for a complete, climate-based checklist.

Open Boise on the interactive map

Check the live 10-day forecast and sunrise/sunset.