Frost Dates for Smithtown, NY 11787

Last spring frost April 11 · First fall frost November 4 · 207 frost-free days · USDA Zone 7b

Frost probability for 11787

Frost10%50%90%
Spring (last frost)April 23April 11March 29
Fall (first frost)October 19November 4November 19

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (35.3 km away); the 50% date is the median year.

Month by month in Smithtown

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 4). Transplant fall brassicas. Sow spinach, arugula, and radishes.
NovemberFirst frost around November 4. 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 207-day season

Frequently Asked Questions

What is the last frost date for Smithtown, NY (ZIP 11787)?

The median last spring frost date for Smithtown, NY (ZIP code 11787) 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 Smithtown, NY?

The median first fall frost date for Smithtown, NY is around November 4. 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 Smithtown, NY?

The frost-free growing season in Smithtown is about 207 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 Smithtown, NY?

Based on frost date patterns, Smithtown 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 Smithtown, NY?

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

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