If you're looking for Tucson average first / last frost dates of the season for gardening, you're in the right place. There's a lot of variation in the dates you'll see cited online, so here I've provided date ranges rather than specific dates.

The daily average high (red line) and low (blue line) temperature,
with 25th to 75th and 10th to 90th percentile bands.

The thin dotted lines are the corresponding average perceived temperatures.

I believe frost date ranges provide more value than hard dates, because you can adjust your planting schedule against the date range based on your personal risk tolerance.

Sometimes risking early spring or late autumn planting can pay off, so factor your risk tolerance in while checking out the average frost date ranges below:

Tucson First Frost Date

Depending on who you ask, Tucson's average first frost date in Autumn falls between:

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November 18th - December 9th

Ramping down your warm season plantings from July through September also provides the same balance between risk and reward of an early Autumn killing frost.

If you're curious what to plant during this time, check out the Tucson Planting Calendars:

bean plants brown leaves from frost flambo next to trellis desert garden
Flambo beans were just starting to produce,
only to be squashed by an early November frost

Tucson Last Frost Date

Depending on who you ask, Tucson's average last frost date in Spring falls between:

February 2nd - March 14th

Ramping up your warm season plantings slowly between February and April provides a balance of risk and reward.


Take a look at the Tucson Planting Calendars for this time period if you want to know what you can plant as you wait for danger of the last frost to pass:

Tucson Average Temperatures

Month Average Low Average High
January 42°F 66°F
February 45°F 70°F
March 49°F 76°F
April 55°F 83°F
May 63°F 92°F
June 72°F 100°F
July 77°F 100°F
August 75°F 97°F
September 70°F 94°F
October 60°F 85°F
November 49°F 74°F
December 43°F 66°F
Average Temperatures for Tucson from WeatherSpark.com,
may vary compared to other sources and stations.

Tucson Gardening Frost Season

In general, prep your Tucson garden for frosts from late-November until mid-March.

If you're a risk-taker, you can temp the fates and bet on a shorter frost season.





Pushing your luck on fall plantings can pay off big if the first frost comes late. Likewise, planting a few weeks early in the spring can get you a big jump on the season if you're willing to risk it for the biscuit.

summer squash and zucchini frost damage brown leaves iced
November 10th early frost in Tucson.
Squash got iced.

I usually treat it like this:

frosts are guaranteed December - February, and outside that I can push my luck on smaller plantings of warm season crops, knowing I might lose some.