Frost Dates for Phoenix, AZ 85032

Last spring frost February 6 · First fall frost December 13 · 310 frost-free days · USDA Zone 9b

Frost probability for 85032

Frost10%50%90%
Spring (last frost)March 18February 6—
Fall (first frost)November 18December 13—

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (23.1 km away); the 50% date is the median year.

Frost dates by ZIP code in Phoenix, AZ

ZIPLast spring frost (50%)First fall frost (50%)Zone
85032February 6December 139b
85041February 8December 510a
85008February 8December 510a
85033February 1December 99b
85037February 1December 99b
85022February 6December 139b
85035February 1December 99b
85009February 8December 510a
85029February 8December 59b
85017February 8December 59b
85042February 8December 510a
85051February 8December 59b
85086February 6December 139b
85015February 8December 59b
85043February 8December 59b
85021February 8December 59b
85027February 6December 1110a
85044February 8December 510a
85018February 8December 510a
85016February 8December 510a
85023February 8December 59b
85020February 8December 510a
85048February 8December 59b
85040February 8December 510a
85050February 6December 1310a
85085February 6December 119b
85031February 1December 99b
85053February 8December 59b
85019February 8December 59b
85024February 6December 1110a
85014February 8December 510a
85013February 8December 59b
85006February 8December 510a
85083February 6December 119b
85028February 8December 510a
85007February 8December 510a
85004February 8December 510a
85003February 8December 510a
85054February 6December 139b
85012February 8December 510a
85045February 8December 510a
85034February 8December 510a
85026February 8December 510a

Month by month in Phoenix

MonthWhat to do
JanuaryStart herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable.
FebruaryLast frost around February 6. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
MarchFrost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
AprilSuccession plant lettuce and greens. Keep beds weeded and watered consistently.
MayHarvest regularly to encourage production. Monitor for pests and disease.
JuneMidsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall.
JulyDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
AugustDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
SeptemberDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
OctoberDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
NovemberFirst fall frost approaching (around December 13). Transplant fall brassicas. Sow spinach, arugula, and radishes.
DecemberFirst frost around December 13. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.

What grows in a 310-day season

Frequently Asked Questions

What is the last frost date for Phoenix, AZ (ZIP 85032)?

The median last spring frost date for Phoenix, AZ (ZIP code 85032) is around February 6. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.

What is the first fall frost date in Phoenix, AZ?

The median first fall frost date for Phoenix, AZ is around December 13. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.

How long is the growing season in Phoenix, AZ?

The frost-free growing season in Phoenix is about 310 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side.

What USDA hardiness zone is Phoenix, AZ?

Based on frost date patterns, Phoenix falls approximately in 9b. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.

When should I start tomatoes indoors in Phoenix, AZ?

Start tomato seeds indoors 6–8 weeks before your last frost date (around February 6). For Phoenix, that's roughly December 12 to December 26. Transplant outdoors 1–2 weeks after your last frost.

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