Tucson U Of A #1, AZ Frost Dates & Growing Season

The two dates every Tucson U Of A #1 garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Feb 11
~50% chance of frost after
First fall frost
Dec 2
~50% chance of frost before
Growing season
294 days
frost-free stretch
USDA zone
≈ 9b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Jan 16 Feb 11 Mar 7
First fall frost Dec 20 Dec 2 Nov 16
Hard freeze (28°F), median last Jan 18 · first Dec 15

Computed from NOAA 1991–2020 climate normals at the TUCSON U OF A #1 station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Tucson U Of A #1

Computed from Tucson U Of A #1's own frost dates. Click any crop for the full zone-9 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Dec 17 – Dec 31 Feb 18 – Feb 25
🫑 Peppers Dec 3 – Dec 17 Feb 25 – Mar 4
🥬 Lettuce Dec 31 – Jan 14 Jan 14 – Jan 28 Jan 14 – Feb 11
🫛 Peas Dec 31 – Jan 14
🥕 Carrots Jan 21 – Feb 11
🥦 Broccoli Dec 24 – Jan 7 Jan 21 – Feb 4
🥬 Kale Dec 31 – Jan 14 Jan 14 – Jan 28 Jan 14 – Jan 28
🥒 Cucumbers Jan 14 – Jan 21 Feb 18 – Feb 25 Feb 18 – Feb 25
🥒 Zucchini Jan 14 – Jan 21 Feb 18 – Feb 25 Feb 18 – Feb 25
🫘 Green Beans (Bush) Feb 18 – Feb 25
🌽 Sweet Corn Feb 18 – Feb 25
🌿 Basil Dec 31 – Jan 14 Feb 18 – Feb 25 Feb 25 – Mar 4
🧄 Garlic Fall: Oct 21 – Nov 18

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Tucson U Of A #1's dates automatically after a lookup.

Reading the season in Tucson U Of A #1

With roughly 294 frost-free days, Tucson U Of A #1 gardens fit long-season crops — melons, winter squash, sweet potatoes — with room left for spring and fall rounds of greens and roots. The first frost around Dec 2 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Tucson U Of A #1, AZ?

The average last spring frost in Tucson U Of A #1 is around Feb 11, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Tucson U Of A #1, AZ?

The average first fall frost in Tucson U Of A #1 arrives around Dec 2. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Tucson U Of A #1?

About 294 frost-free days on average, from Feb 11 to Dec 2. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Tucson U Of A #1 in?

USDA zone 9b on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.