Imperial Co Airport, CA Frost Dates & Growing Season

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

Last spring frost
Jan 14
~50% chance of frost after
First fall frost
Dec 24
~50% chance of frost before
Growing season
344 days
frost-free stretch
USDA zone
≈ 10b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Dec 18 Jan 14 Feb 15
First fall frost Jan 24 Dec 24 Dec 2
Hard freeze (28°F), median last Jan 8 · first Jan 5

Computed from NOAA 1991–2020 climate normals at the IMPERIAL CO AP 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 Imperial Co Airport

Computed from Imperial Co Airport's own frost dates. Click any crop for the full zone-10 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Nov 19 – Dec 3 Jan 21 – Jan 28
🫑 Peppers Nov 5 – Nov 19 Jan 28 – Feb 4
🥬 Lettuce Dec 3 – Dec 17 Dec 17 – Dec 31 Dec 17 – Jan 14
🫛 Peas Dec 3 – Dec 17
🥕 Carrots Dec 24 – Jan 14
🥦 Broccoli Nov 26 – Dec 10 Dec 24 – Jan 7
🥬 Kale Dec 3 – Dec 17 Dec 17 – Dec 31 Dec 17 – Dec 31
🥒 Cucumbers Dec 17 – Dec 24 Jan 21 – Jan 28 Jan 21 – Jan 28
🥒 Zucchini Dec 17 – Dec 24 Jan 21 – Jan 28 Jan 21 – Jan 28
🫘 Green Beans (Bush) Jan 21 – Jan 28
🌽 Sweet Corn Jan 21 – Jan 28
🌿 Basil Dec 3 – Dec 17 Jan 21 – Jan 28 Jan 28 – Feb 4
🧄 Garlic Fall: Nov 12 – Dec 10

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 Imperial Co Airport's dates automatically after a lookup.

Reading the season in Imperial Co Airport

With roughly 344 frost-free days, Imperial Co Airport 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 24 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Imperial Co Airport, CA?

The average last spring frost in Imperial Co Airport is around Jan 14, 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 Imperial Co Airport, CA?

The average first fall frost in Imperial Co Airport arrives around Dec 24. 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 Imperial Co Airport?

About 344 frost-free days on average, from Jan 14 to Dec 24. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Imperial Co Airport in?

USDA zone 10b 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.