Frost Dates for Half Moon Bay, CA 94019

Last spring frost January 28 · First fall frost November 30 · 306 frost-free days · USDA Zone 10a

Frost probability for 94019

Frost10%50%90%
Spring (last frost)March 7January 28January 12
Fall (first frost)November 18November 30January 10

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (14.8 km away); the 50% date is the median year.

Month by month in Half Moon Bay

MonthWhat to do
JanuaryLast frost around January 28. 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 30). Transplant fall brassicas. Sow spinach, arugula, and radishes.
NovemberFirst frost around November 30. 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 306-day season

Frequently Asked Questions

What is the last frost date for Half Moon Bay, CA (ZIP 94019)?

The median last spring frost date for Half Moon Bay, CA (ZIP code 94019) is around January 28. 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 Half Moon Bay, CA?

The median first fall frost date for Half Moon Bay, CA is around November 30. 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 Half Moon Bay, CA?

The frost-free growing season in Half Moon Bay is about 306 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 Half Moon Bay, CA?

Based on frost date patterns, Half Moon Bay falls approximately in 10a. 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 Half Moon Bay, CA?

Start tomato seeds indoors 6–8 weeks before your last frost date (around January 28). For Half Moon Bay, that's roughly December 3 to December 17. Transplant outdoors 1–2 weeks after your last frost.

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