Frost Dates for Ketchikan, AK 99901

Last spring frost April 21 · First fall frost October 27 · 189 frost-free days · USDA Zone 7b

Frost probability for 99901

Frost10%50%90%
Spring (last frost)May 7April 21March 30
Fall (first frost)October 12October 27November 12

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (29.5 km away); the 50% date is the median year.

Month by month in Ketchikan

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 21). 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 21. 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.
SeptemberFirst fall frost approaching (around October 27). Transplant fall brassicas. Sow spinach, arugula, and radishes.
OctoberFirst frost around October 27. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.
NovemberHarvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year.
DecemberClean up spent plants. Add compost to beds. Rest, review, and plan next year's garden.

What grows in a 189-day season

Frequently Asked Questions

What is the last frost date for Ketchikan, AK (ZIP 99901)?

The median last spring frost date for Ketchikan, AK (ZIP code 99901) is around April 21. 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 Ketchikan, AK?

The median first fall frost date for Ketchikan, AK is around October 27. 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 Ketchikan, AK?

The frost-free growing season in Ketchikan is about 189 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 Ketchikan, AK?

Based on frost date patterns, Ketchikan falls approximately in 7b. 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 Ketchikan, AK?

Start tomato seeds indoors 6–8 weeks before your last frost date (around April 21). For Ketchikan, that's roughly February 25 to March 10. Transplant outdoors 1–2 weeks after your last frost.

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