Harman US

Frost Dates for Scottsdale, AZ

Last spring frost
Jan 6
First fall frost
Dec 26
Growing season
353 days
Hardiness zone
10a

In an average year around Scottsdale, AZ, the last spring frost (32°F) is about Jan 6 and the first fall frost is about Dec 26, giving roughly a 353-day growing season. To be safe most years, wait until Dec 16 before setting out tender plants.

Last spring frost

Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.

Last spring frost - Scottsdale, AZ
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Feb 26 Jan 30 Jan 3
Freeze (32°F) Feb 7 Jan 6 Dec 16
Hard (28°F) Jan 20 Jan 2 Dec 15
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Feb 26 Feb 16 Feb 10 Feb 3 Jan 30 Jan 23 Jan 17 Jan 11 Jan 3
32°F Feb 7 Jan 26 Jan 18 Jan 12 Jan 6 Jan 2 Dec 30 Dec 25 Dec 16
28°F Jan 20 Jan 12 Jan 8 Jan 5 Jan 2 Jan 1 Dec 28 Dec 24 Dec 15

First fall frost

Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.

First fall frost - Scottsdale, AZ
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Nov 25 Dec 11 Dec 30
Freeze (32°F) Dec 4 Dec 26 Jan 20
Hard (28°F) Dec 14 Jan 1 Jan 17
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Nov 25 Nov 30 Dec 4 Dec 8 Dec 11 Dec 14 Dec 18 Dec 23 Dec 30
32°F Dec 4 Dec 11 Dec 17 Dec 22 Dec 26 Dec 29 Jan 1 Jan 7 Jan 20
28°F Dec 14 Dec 21 Dec 27 Dec 31 Jan 1 Jan 4 Jan 6 Jan 10 Jan 17

Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.

Where this data comes from

These dates are computed from the nearest official weather station with long-term records: Scottsdale Muni Ap, Az, about 1.6 miles away@if(!empty($station['elevation_ft'])), at 1,473 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

@endif
How we calculate these dates

Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.

Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.

Frequently asked questions

When is the last frost in Scottsdale, AZ?

On average, the last spring frost (32°F) around Scottsdale, AZ is about Jan 6. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 16.

When is the first frost in the fall?

The first fall frost around Scottsdale, AZ typically arrives about Dec 26. Count back by a crop's days to maturity to find the latest date you can plant it.

When can I plant tomatoes and other tender crops?

Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Jan 6 on average, or Dec 16 to be safe most years.

How long is the growing season here?

The frost-free growing season (between the last spring and first fall 32°F frost) is about 353 days in a typical year.

Are these dates a forecast for this year?

No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.

Local weather for 85260 Planting calendar → Arizona frost dates →

Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026