Frost Dates for Kelseyville, CA 95451

Last spring frost April 11 · First fall frost November 3 · 206 frost-free days · USDA Zone 9b

Frost probability for 95451

Frost10%50%90%
Spring (last frost)May 6April 11March 16
Fall (first frost)October 15November 3November 14

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (20.6 km away); the 50% date is the median year.

Month by month in Kelseyville

MonthWhat to do
JanuaryPlan your garden layout and order seeds. Research varieties suited to your frost dates.
FebruaryStart peppers and eggplant indoors 8–10 weeks before your last frost (around April 11). Start tomatoes about two weeks later, 6–8 weeks before last frost.
MarchStart herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable.
AprilLast frost around April 11. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
MayFrost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
JuneSuccession plant lettuce and greens. Keep beds weeded and watered consistently.
JulyHarvest regularly to encourage production. Monitor for pests and disease.
AugustMidsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall.
SeptemberDirect sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
OctoberFirst fall frost approaching (around November 3). Transplant fall brassicas. Sow spinach, arugula, and radishes.
NovemberFirst frost around November 3. 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 206-day season

Frequently Asked Questions

What is the last frost date for Kelseyville, CA (ZIP 95451)?

The median last spring frost date for Kelseyville, CA (ZIP code 95451) is around April 11. 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 Kelseyville, CA?

The median first fall frost date for Kelseyville, CA is around November 3. 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 Kelseyville, CA?

The frost-free growing season in Kelseyville is about 206 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 Kelseyville, CA?

Based on frost date patterns, Kelseyville 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 Kelseyville, CA?

Start tomato seeds indoors 6–8 weeks before your last frost date (around April 11). For Kelseyville, that's roughly February 15 to February 29. Transplant outdoors 1–2 weeks after your last frost.

Nearby and related