Flagstaff weather in September
“The kind of pleasant weather you build a trip around.”
Roughly 7 rainy days across the month, on average.
September in Flagstaff brings mild, pleasant weather with daytime temperatures averaging 24°C (75°F) and cooler nights dropping to 11.8°C (53°F). Expect moderate rainfall of 33.7mm spread across about 6.5 days, so pack layers and a light rain jacket. With 11.6 hours of sunshine daily, you'll enjoy mostly clear skies perfect for outdoor exploration.
This is the tail end of Flagstaff's summer season, offering a sweet spot between peak July-August crowds and the autumn rush. The town's cultural calendar winds down from major summer festivals, creating a relaxed atmosphere. Local hiking trails are still accessible, and the ponderosa pine forests remain lush and green.
For travelers planning a 2026 visit, September is ideal if you want comfortable weather without summer heat or winter snow. Book accommodations early as Labor Day weekend can draw crowds, but weekdays remain quieter. The weather is stable enough for multi-day outdoor adventures while remaining cool enough for active sightseeing.
What to pack for Flagstaff in September
Layer smartly for Flagstaff's September temperature swings. Mornings and evenings are cool, while afternoons warm up nicely. Bring versatile pieces you can add or remove as needed, plus rain protection for afternoon showers.
- Lightweight merino wool t-shirt
- Fleece pullover or cardigan
- Water-resistant rain jacket
- Hiking pants or jeans
- Comfortable walking shoes with good grip
What to pack for Flagstaff in September
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Where to stay in Flagstaff
We don't review individual hotels — plenty of people do that well. What we do is send you to compare rooms in Flagstaff across trusted platforms.
Compare hotels on Booking.com→Things worth doing
Hiking the San Francisco Peaks, exploring Walnut Canyon National Monument, visiting downtown Flagstaff's breweries and galleries, stargazing at Lowell Observatory.
September vs. the rest of the year
How this month compares in Flagstaff. Tap any month to read more.
highlighted months are among the best time to visit.
Best time to visit Flagstaff
While September has its own character in Flagstaff, the data-backed best months to visit Flagstaff are April, May, June, July. These months combine the most favourable temperatures, rainfall, and sunshine across a ten-year climate record.
See the full best-time-to-visit guide for FlagstaffOther places with a similar climate right now
Flagstaff in September — FAQ
Q01Is September a good time to visit Flagstaff?
Is September a good time to visit Flagstaff?
Yes — this is one of the best months of the year to visit. In September, Flagstaff averages a high of 24°C (75°F) and a low of 12°C (53°F), with 34mm of rainfall across roughly 7 rainy days.
Q02What is the average temperature in Flagstaff in September?
What is the average temperature in Flagstaff in September?
The average high temperature in Flagstaff during September is 24°C (75°F), with an average low of 12°C (53°F). These figures are averaged from ten years of daily records (2015–2024, Open-Meteo Archive).
Q03How many rainy days does Flagstaff have in September?
How many rainy days does Flagstaff have in September?
Flagstaff averages approximately 7 rainy days in September, with a total monthly rainfall of about 34mm. This is based on daily precipitation records where days with 1mm or more of rain are counted as rainy days.
Q04What should I pack for Flagstaff in September?
What should I pack for Flagstaff in September?
For Flagstaff in September, pack layered clothing for changing temperatures, sunscreen and sunglasses, comfortable walking shoes. These recommendations are based on the ten-year weather averages for this specific month.
Q05How crowded is Flagstaff in September?
How crowded is Flagstaff in September?
Tourist crowds in Flagstaff during September are typically moderate — shoulder season, a sweet spot between crowds and weather. Consider this when planning accommodation — prices track crowd levels closely.