When to plant in Tiffin, OH
USDA Zone 6aEverything below — frost dates, hardiness zone, and what to plant when in Tiffin, Ohio — is derived from the closest NOAA station with complete climate normals.
Zone 6a means Tiffin sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
The average first fall frost in Tiffin is now 5 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
TIFFIN · 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 Tiffin’s own odds, recorded at TIFFIN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 17 | May 2 | Apr 18 | Sep 30 | Oct 11 | Oct 24 |
| 32°F | May 7 | Apr 23 | Apr 8 | Oct 9 | Oct 23 | Nov 5 |
| 28°F | Apr 26 | Apr 11 | Mar 28 | Oct 21 | Nov 3 | Nov 19 |
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 Tiffin, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 25 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.
Tiffin planting FAQ
When is the last spring frost in Tiffin, OH?
Tiffin's average last spring frost falls near April 23 — 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 Tiffin, OH?
The first fall frost in Tiffin typically arrives around October 23 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Tiffin in?
Tiffin 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 Tiffin?
There are roughly 183 frost-free days in Tiffin (a moderate growing season), running from the average last frost around April 23 to the first fall frost near October 23.
When should I plant tomatoes in Tiffin?
In Tiffin, start tomato seeds indoors around February 26–March 12, then transplant seedlings outdoors around April 30 once the danger of frost has passed.
Never miss a window in Tiffin
An email when it’s time to start seeds, transplant, and sow — timed to Tiffin’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at TIFFIN, 1 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 Tiffin, OH — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00338313. Retrieved from https://blissgarden.com/ohio/tiffin.