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Will it freeze in Flagstaff in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 32°F (Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST).
Tonight: forecast low 32°F. Freeze.
NWS forecast period: Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST.
7 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 32°F Freeze · Mostly Cloudy
- Fri, Nov 6 34°F Frost possible · Mostly Clear
- Sat, Nov 7 33°F Frost possible · Clear
- Sun, Nov 8 34°F Frost possible · Mostly Clear
- Mon, Nov 9 35°F Frost possible · Mostly Clear
- Tue, Nov 10 35°F Frost possible · Mostly Clear
- Wed, Nov 11 35°F Frost possible · Mostly Clear
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Flagstaff
The median first fall hard-freeze date (28°F) is October 9, from NOAA’s 1991–2020 Climate Normals at Flagstaff Pulliam Airport. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Jun 3 · Jun 16 · Jul 1 | Sep 6 · Sep 19 · Sep 28 | 92 days |
| 32°F freeze | May 21 · Jun 4 · Jun 19 | Sep 16 · Sep 28 · Oct 9 | 115 days |
| 28°F hard freeze | May 1 · May 20 · Jun 6 | Sep 28 · Oct 9 · Oct 22 | 139 days |
Average high temperature by month
1991–2020 normals at Flagstaff Pulliam Airport
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Flagstaff, AZ come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Flagstaff Pulliam Airport (station USW00003103, elevation 7,003 ft), 3.9 mi from Flagstaff. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Flagstaff
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Sedona, AZ | 25 mi | Apr 1 | Nov 17 |
| Cottonwood, AZ | 37 mi | Mar 30 | Nov 10 |
| Camp Verde, AZ | 45 mi | Apr 16 | Oct 30 |
| Winslow, AZ | 53 mi | Apr 27 | Oct 18 |
| Chino Valley, AZ | 54 mi | Apr 27 | Oct 24 |
| Prescott Valley, AZ | 57 mi | Apr 30 | Oct 20 |
| Prescott, AZ | 62 mi | Apr 30 | Oct 20 |
| Payson, AZ | 67 mi | Apr 29 | Oct 24 |
| Cave Creek, AZ | 96 mi | Feb 4 | Dec 16 |
| Snowflake, AZ | 98 mi | May 11 | Oct 10 |
Frequently asked questions
When is the last frost in Flagstaff?
On average, the last spring frost (32°F) in Flagstaff is around June 4. In about 1 year in 10 it comes after June 19, and in 9 years in 10 it comes after May 21.
When is the first frost in Flagstaff?
The first fall frost (32°F) usually arrives around September 28. There’s a 10% chance of a freeze by September 16 and a 90% chance by October 9.
Can it frost in Flagstaff after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after June 16.
What growing zone is Flagstaff?
Flagstaff is in USDA Plant Hardiness Zone 6a (average annual extreme minimum temperature −10 to −5°F), based on the 2023 USDA map for ZIP code 86005. See growing zones in Arizona.
More: all Arizona frost dates · Arizona growing zones · UV index today in Flagstaff · frost vs. freeze