When to plant in Smithtown, NY
USDA Zone 7bEverything below — frost dates, hardiness zone, and what to plant when in Smithtown, New York — is derived from the closest NOAA station with complete climate normals.
In zone 7b, Smithtown supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
ISLIP LI MACARTHUR AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Smithtown’s own odds, recorded at ISLIP LI MACARTHUR AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 7 | Apr 23 | Apr 11 | Oct 8 | Oct 21 | Nov 4 |
| 32°F | Apr 25 | Apr 10 | Mar 31 | Oct 18 | Nov 2 | Nov 15 |
| 28°F | Apr 12 | Mar 30 | Mar 14 | Nov 1 | Nov 14 | Dec 1 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Smithtown, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Smithtown planting FAQ
When is the last spring frost in Smithtown, NY?
Smithtown's average last spring frost falls near April 10 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Smithtown, NY?
Expect Smithtown's first fall frost near November 2 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Smithtown in?
Smithtown is in USDA hardiness zone 7b. In zone 7b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Smithtown?
Smithtown has about 206 frost-free days — a moderate growing season — between the average last spring frost (April 10) and first fall frost (November 2).
When should I plant tomatoes in Smithtown?
For Smithtown, sow tomatoes indoors about February 13–February 27 and move the seedlings out around April 17, after the last spring frost.
Never miss a window in Smithtown
An email when it’s time to start seeds, transplant, and sow — timed to Smithtown’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Hauppauge · 4 km
- Kings Park · 4 km
- Nesconset · 6 km
- Commack · 6 km
- St. James · 6 km
- Lake Grove · 8 km
- Central Islip · 8 km
- Fort Salonga · 9 km
Frost dates recorded at ISLIP LI MACARTHUR AP, 12 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Smithtown, NY — Frost Dates & Zone 7b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00004781. Retrieved from https://blissgarden.com/new-york/smithtown.