Roosevelt 1 S, AZ Frost Dates & Growing Season

The two dates every Roosevelt 1 S garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Jan 17
~50% chance of frost after
First fall frost
Dec 25
~50% chance of frost before
Growing season
342 days
frost-free stretch
USDA zone
≈ 9b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Dec 21 Jan 17 Feb 18
First fall frost Jan 27 Dec 25 Dec 5
Hard freeze (28°F), median last Jan 14 · first Jan 10

Computed from NOAA 1991–2020 climate normals at the ROOSEVELT 1 S 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 Roosevelt 1 S

Computed from Roosevelt 1 S'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 Nov 22 – Dec 6 Jan 24 – Jan 31
🫑 Peppers Nov 8 – Nov 22 Jan 31 – Feb 7
🥬 Lettuce Dec 6 – Dec 20 Dec 20 – Jan 3 Dec 20 – Jan 17
🫛 Peas Dec 6 – Dec 20
🥕 Carrots Dec 27 – Jan 17
🥦 Broccoli Nov 29 – Dec 13 Dec 27 – Jan 10
🥬 Kale Dec 6 – Dec 20 Dec 20 – Jan 3 Dec 20 – Jan 3
🥒 Cucumbers Dec 20 – Dec 27 Jan 24 – Jan 31 Jan 24 – Jan 31
🥒 Zucchini Dec 20 – Dec 27 Jan 24 – Jan 31 Jan 24 – Jan 31
🫘 Green Beans (Bush) Jan 24 – Jan 31
🌽 Sweet Corn Jan 24 – Jan 31
🌿 Basil Dec 6 – Dec 20 Jan 24 – Jan 31 Jan 31 – Feb 7
🧄 Garlic Fall: Nov 13 – Dec 11

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 Roosevelt 1 S's dates automatically after a lookup.

Reading the season in Roosevelt 1 S

With roughly 342 frost-free days, Roosevelt 1 S 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 25 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Roosevelt 1 S, AZ?

The average last spring frost in Roosevelt 1 S is around Jan 17, 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 Roosevelt 1 S, AZ?

The average first fall frost in Roosevelt 1 S arrives around Dec 25. 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 Roosevelt 1 S?

About 342 frost-free days on average, from Jan 17 to Dec 25. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Roosevelt 1 S 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.