Frost dates 2026–2027

Frost dates for Somerton, Arizona

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Yuma Quartermaster Depot, 9.7 mi away (close match).

Last spring frostJan 8
First fall frostDec 28
362 frost-free days
Last spring frostJan 81 year in 10 after Feb 19
First fall frostDec 281 year in 10 by Dec 11
Growing season362 daysbetween median 32°F dates
Hardiness zoneZone 10a30 to 35°F average extreme low

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Will it freeze in Somerton in the next 7 nights?

No overnight lows at or below 32°F are forecast in Somerton during the next 7 nights in the available NWS frost forecast.

Tonight: forecast low 56°F. Above 36°F.

NWS forecast period: Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST.

No nights at or below 36°F in the National Weather Service forecast for the next 7 nights.

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 Somerton

Most years have no 28°F hard freeze at Yuma Quartermaster Depot, according to NOAA’s 1991–2020 Climate Normals. Check the short-term forecast above during cold snaps.

TemperatureLast 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 Dec 25 · Jan 28 · Feb 28 Nov 29 · Dec 16 · Jan 5 324 days
32°F freeze Dec 17 · Jan 8 · Feb 19 Dec 11 · Dec 28 · Feb 7 362 days
28°F hard freeze Dec 19 · Jan 1 · Feb 16 Dec 16 · Dec 31 · Feb 10 365 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00029656. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Yuma Quartermaster Depot

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 Somerton, AZ come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Yuma Quartermaster Depot (station USC00029656, elevation 160 ft), 9.7 mi from Somerton. 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 Somerton

CityDistanceLast spring frostFirst fall frost
San Luis, AZ 8.1 mi Jan 8 Dec 28
Yuma, AZ 12 mi Jan 8 Dec 28
Holtville, CA 42 mi Jan 3 Dec 27
Calexico, CA 47 mi Jan 3 Dec 27
El Centro, CA 52 mi Jan 3 Dec 27
Imperial, CA 53 mi Jan 14 Dec 24
Brawley, CA 55 mi Jan 16 Dec 19
Calipatria, CA 60 mi Jan 16 Dec 19
Blythe, CA 73 mi Jan 25 Dec 12
Coachella, CA 112 mi rare rare

Frequently asked questions

When is the last frost in Somerton?

On average, the last spring frost (32°F) in Somerton is around January 8. In about 1 year in 10 it comes after February 19, and in 9 years in 10 it comes after December 17.

When is the first frost in Somerton?

The first fall frost (32°F) usually arrives around December 28. There’s a 10% chance of a freeze by December 11 and a 90% chance by February 7.

Can it frost in Somerton 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 January 28.

What growing zone is Somerton?

Somerton is in USDA Plant Hardiness Zone 10a (average annual extreme minimum temperature 30 to 35°F), based on the 2023 USDA map for ZIP code 85350. See growing zones in Arizona.

More: all Arizona frost dates · Arizona growing zones · frost vs. freeze