Frost dates for 45231Cincinnati, OH
The average last spring frost in Cincinnati is April 17 and the average first fall frost is October 26, giving a typical growing season of about 191 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 17
- Average first fall frost
- Oct 26
- Growing season
- 191 days
Safer after May 5 (1-in-10 risk)
Possible by Oct 11 (1-in-10 risk)
First frost typically in 9 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 14 · Apr 29 · May 13 | Oct 3 · Oct 16 · Oct 29 | 170 days | 100% |
| Frost / freeze (32°F) | Apr 2 · Apr 17 · May 5 | Oct 11 · Oct 26 · Nov 7 | 191 days | 100% |
| Hard freeze (28°F) | Mar 20 · Apr 4 · Apr 21 | Oct 22 · Nov 4 · Nov 22 | 214 days | 100% |
Planting calendar for Cincinnati
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 17 – May 23 |
| Tomatoes | Transplant outdoors | May 3 – Jul 6 |
| Peppers | Start seeds indoors | Mar 17 – Apr 17 |
| Peppers | Transplant outdoors | May 17 – Jun 17 |
| Eggplant | Start seeds indoors | Apr 3 – May 2 |
| Eggplant | Transplant outdoors | May 17 – Jun 17 |
| Cucumbers | Sow outdoors | May 17 – Jul 16 |
| Summer squash | Sow outdoors | May 3 – Jun 17 |
| Winter squash & pumpkins | Sow outdoors | May 17 – Jun 17 |
| Snap beans | Sow outdoors | May 3 – Aug 8 |
| Sweet corn | Sow outdoors | May 3 – Jul 6 |
| Watermelon & cantaloupe | Sow outdoors | May 17 – Jun 17 |
| Okra | Sow outdoors | May 10 – Jun 2 |
| Peas | Sow outdoors (spring) | Mar 17 – May 2 |
| Potatoes | Plant outdoors (spring) | Mar 17 – May 17 |
| Onions | Start seeds indoors (spring) | Feb 3 – Mar 2 |
| Onions | Transplant outdoors (spring) | Apr 3 – May 2 |
| Broccoli | Start seeds indoors (spring) | Feb 27 – Apr 2 |
| Broccoli | Transplant outdoors (spring) | Apr 3 – May 2 |
| Broccoli | Start seeds indoors (fall) | Jun 26 – Jul 6 |
| Broccoli | Transplant outdoors (fall) | Jul 26 – Aug 6 |
| Cabbage | Start seeds indoors (spring) | Feb 17 – Mar 17 |
| Cabbage | Transplant outdoors (spring) | Mar 17 – Apr 17 |
| Cabbage | Start seeds indoors (fall) | Jun 16 – Jul 16 |
| Cabbage | Transplant outdoors (fall) | Jul 16 – Aug 16 |
| Leaf lettuce | Sow outdoors (spring) | Mar 17 – Jun 2 |
| Leaf lettuce | Sow outdoors (fall) | Jul 16 – Sep 1 |
| Spinach | Sow outdoors (spring) | Mar 10 – Apr 23 |
| Spinach | Sow outdoors (fall) | Aug 2 – Sep 6 |
| Radishes | Sow outdoors (spring) | Mar 17 – May 7 |
| Radishes | Sow outdoors (fall) | Jul 16 – Sep 16 |
| Kale | Sow outdoors (spring) | Apr 3 – Apr 23 |
| Kale | Sow outdoors (fall) | Jul 9 – Aug 16 |
| Carrots | Sow outdoors (spring) | Apr 17 – Jun 2 |
| Carrots | Sow outdoors (fall) | Jun 16 – Aug 1 |
| Garlic | Plant outdoors (fall) | Oct 16 – Nov 16 |
Where these dates come from
ZIP code 45231 is matched to the NOAA station Cheviot, OH, 11.9 km away, at 891 ft elevation (94 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cheviot, OH (used) | 891 ft | Apr 17 | Oct 26 |
| Fairfield, OH | 575 ft | Apr 19 | Oct 22 |
| Hamilton Butler Co Rgnl Ap, OH | 634 ft | Apr 22 | Oct 18 |
| Cheviot 3 W, OH | 853 ft | Apr 16 | Oct 28 |
Frost dates near Cincinnati
- Cincinnati, OH 45218 · last Apr 22, first Oct 18
- Fairfield, OH 45014 · last Apr 22, first Oct 18
- Ross, OH 45061 · last Apr 19, first Oct 22
- Hamilton, OH 45015 · last Apr 22, first Oct 18
- Miamitown, OH 45041 · last Apr 13, first Oct 31
- West Chester, OH 45071 · last Apr 22, first Oct 18
- Dayton, KY 41074 · last Apr 16, first Oct 25
- Bellevue, KY 41073 · last Apr 16, first Oct 25
Frequently asked questions
- When is the last frost in Cincinnati, OH?
- For ZIP code 45231, the average last spring frost (32°F) is April 17, based on NOAA 1991-2020 climate normals for the Cheviot, OH weather station. There is a 1-in-10 chance of a frost after May 5.
- When is the first frost in Cincinnati, OH?
- The average first fall frost (32°F) is October 26. There is a 1-in-10 chance of frost by October 11, so tender plants are at risk from that point on.
- How long is the growing season in 45231?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 191 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.