Frost Dates for Twentynine Palms, CA 92278

Twentynine Palms has 2 ZIP codes. The Twentynine Palms, CA frost page lists all of them with their dates.

Last spring frost January 10 · First fall frost November 20 · 314 frost-free days · USDA Zone 9b

Frost probability for 92278

Frost10%50%90%
Spring (last frost)March 7January 10—
Fall (first frost)November 18November 20—

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (60.3 km away); the 50% date is the median year.

Month by month in Twentynine Palms

MonthWhat to do
JanuaryLast frost around January 10. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
FebruaryFrost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
MarchSuccession plant lettuce and greens. Keep beds weeded and watered consistently.
AprilHarvest regularly to encourage production. Monitor for pests and disease.
MayMidsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall.
JuneDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
JulyDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
AugustDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
SeptemberDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
OctoberFirst fall frost approaching (around November 20). Transplant fall brassicas. Sow spinach, arugula, and radishes.
NovemberFirst frost around November 20. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.
DecemberHarvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year.

What grows in a 314-day season

Frequently Asked Questions

What is the last frost date for Twentynine Palms, CA (ZIP 92278)?

The median last spring frost date for Twentynine Palms, CA (ZIP code 92278) is around January 10. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.

What is the first fall frost date in Twentynine Palms, CA?

The median first fall frost date for Twentynine Palms, CA is around November 20. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.

How long is the growing season in Twentynine Palms, CA?

The frost-free growing season in Twentynine Palms is about 314 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side.

What USDA hardiness zone is Twentynine Palms, CA?

Based on frost date patterns, Twentynine Palms falls approximately in 9b. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.

When should I start tomatoes indoors in Twentynine Palms, CA?

Start tomato seeds indoors 6–8 weeks before your last frost date (around January 10). For Twentynine Palms, that's roughly November 15 to November 29. Transplant outdoors 1–2 weeks after your last frost.

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