When to plant in Oswego, NY
USDA Zone 6aEverything below — frost dates, hardiness zone, and what to plant when in Oswego, New York — is derived from the closest NOAA station with complete climate normals.
Zone 6a means Oswego sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
OSWEGO · 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 Oswego’s own odds, recorded at OSWEGO.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 19 | May 4 | Apr 23 | Sep 29 | Oct 13 | Oct 30 |
| 32°F | May 7 | Apr 22 | Apr 9 | Oct 9 | Oct 29 | Nov 11 |
| 28°F | Apr 22 | Apr 10 | Mar 31 | Oct 29 | Nov 10 | Nov 26 |
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 Oswego, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 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.
Oswego planting FAQ
When is the last spring frost in Oswego, NY?
Oswego's average last spring frost falls near April 22 — 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 Oswego, NY?
Expect Oswego's first fall frost near October 29 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Oswego in?
Oswego is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Oswego?
There are roughly 190 frost-free days in Oswego (a moderate growing season), running from the average last frost around April 22 to the first fall frost near October 29.
When should I plant tomatoes in Oswego?
In Oswego, start tomato seeds indoors around February 25–March 11, then transplant seedlings outdoors around April 29 once the danger of frost has passed.
Never miss a window in Oswego
An email when it’s time to start seeds, transplant, and sow — timed to Oswego’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at OSWEGO, 3 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 Oswego, NY — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00306314. Retrieved from https://blissgarden.com/new-york/oswego.