Flagstaff in August

In August, Flagstaff averages 27°C (80°F) during the day and 15°C (58°F) at night, with around 12 days of rain (71 mm total).

High season

Conditions are warm and beach-friendly. Plan for unsettled weather and bring rain gear.

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

27°C
Avg high
15°C
Avg low
12
Rain days
71 mm
Rainfall

How August compares to the rest of the year in Flagstaff

3rd
warmest month of the 12
2nd
wettest month of the 12
15%
of yearly rainfall falls in August
13 h 30 min
daylight on the 15th

August is one of the warmest months in Flagstaff (3rd of 12) and one of the wettest months (2nd of 12). Daytime temperature runs 10°C above the annual average (17°C). August runs 2°C cooler than July (28°C) and cools 3°C in September (24°C).

August sunrise & sunset in Flagstaff

🌅
Sunrise (15th)
5:46 AM
🌇
Sunset (15th)
7:15 PM
Day length
13 h 30 min

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

Photography light in Flagstaff — August

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

🌅 Blue hour (AM)
4:46 AM – 5:26 AM
🌄 Golden hour (AM)
5:26 AM – 6:26 AM
🌇 Golden hour (PM)
6:35 PM – 7:35 PM
🌆 Blue hour (PM)
7:35 PM – 8:15 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Flagstaff.

📅 When to book — Flagstaff 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 (High season) and Flagstaff's popularity.

✈ Flights — lead time
2-3 months
Prices are above off-season but not the absolute peak. Tuesday/Wednesday departures are usually cheaper than weekend ones. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
2-3 months
Wide selection still available at this lead time. Premium properties book first; consider 'last-minute deal' availability at 2-week mark if your dates are flexible.

Crowds & pricing — August in Flagstaff

High season

This is a busy month in Flagstaff — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.

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

Sun & mosquito risk — August in Flagstaff

☀️ UV Index (noon, 15th)
11.8
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●○
High
Peak mosquito activity. DEET 30%+, long sleeves at dawn/dusk, sleep under nets if rural.

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.

Flagstaff in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 6°C / 42°F -4°C / 24°F 48 mm 7
February 8°C / 46°F -3°C / 26°F 44 mm 5
March 11°C / 51°F -1°C / 31°F 51 mm 7
April 17°C / 62°F 3°C / 38°F 15 mm 4
May 20°C / 68°F 7°C / 44°F 30 mm 7
June 28°C / 82°F 13°C / 56°F 11 mm 3
July 28°C / 83°F 16°C / 60°F 72 mm 13
August 27°C / 80°F 15°C / 58°F 71 mm 12
September 24°C / 75°F 12°C / 54°F 39 mm 7
October 18°C / 64°F 6°C / 43°F 27 mm 6
November 12°C / 53°F 1°C / 34°F 29 mm 4
December 6°C / 44°F -3°C / 27°F 41 mm 6

Other cities with similar August weather

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

Frequently asked questions

How hot is Flagstaff in August?

In August, Flagstaff averages a high of 27°C (80°F) and a low of 15°C (58°F) — generally warm.

Does it rain a lot in Flagstaff in August?

August can be fairly wet in Flagstaff, with about 12 rainy days on average.

Is August a good time to visit Flagstaff?

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

What should I pack for Flagstaff in August?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full August packing list for Flagstaff for a complete, climate-based checklist.

Open Flagstaff on the interactive map

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