Tombstone, AZ Frost Dates & Growing Season

The two dates every Tombstone garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Mar 4
~50% chance of frost after
First fall frost
Nov 29
~50% chance of frost before
Growing season
270 days
frost-free stretch
USDA zone
≈ 9b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Feb 3 Mar 4 Mar 31
First fall frost Dec 17 Nov 29 Nov 12
Hard freeze (28°F), median last Feb 8 · first Dec 12

Computed from NOAA 1991–2020 climate normals at the TOMBSTONE 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 Tombstone

Computed from Tombstone'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 Jan 7 – Jan 21 Mar 11 – Mar 18
🫑 Peppers Dec 24 – Jan 7 Mar 18 – Mar 25
🥬 Lettuce Jan 21 – Feb 4 Feb 4 – Feb 18 Feb 4 – Mar 4
🫛 Peas Jan 21 – Feb 4
🥕 Carrots Feb 11 – Mar 4
🥦 Broccoli Jan 14 – Jan 28 Feb 11 – Feb 25
🥬 Kale Jan 21 – Feb 4 Feb 4 – Feb 18 Feb 4 – Feb 18
🥒 Cucumbers Feb 4 – Feb 11 Mar 11 – Mar 18 Mar 11 – Mar 18
🥒 Zucchini Feb 4 – Feb 11 Mar 11 – Mar 18 Mar 11 – Mar 18
🫘 Green Beans (Bush) Mar 11 – Mar 18
🌽 Sweet Corn Mar 11 – Mar 18
🌿 Basil Jan 21 – Feb 4 Mar 11 – Mar 18 Mar 18 – Mar 25
🧄 Garlic Fall: Oct 18 – Nov 15

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 Tombstone's dates automatically after a lookup.

Reading the season in Tombstone

With roughly 270 frost-free days, Tombstone 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 Nov 29 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Tombstone, AZ?

The average last spring frost in Tombstone is around Mar 4, 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 Tombstone, AZ?

The average first fall frost in Tombstone arrives around Nov 29. 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 Tombstone?

About 270 frost-free days on average, from Mar 4 to Nov 29. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Tombstone 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.