Frost dates for 45662Portsmouth, OH
The average last spring frost in Portsmouth is April 17 and the average first fall frost is October 25, 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 25
- Growing season
- 191 days
Safer after May 5 (1-in-10 risk)
Possible by Oct 11 (1-in-10 risk)
Last frost typically in 167 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 13 · Apr 30 · May 15 | Oct 3 · Oct 15 · Oct 27 | 168 days | 100% |
| Frost / freeze (32°F) | Apr 3 · Apr 17 · May 5 | Oct 11 · Oct 25 · Nov 6 | 191 days | 100% |
| Hard freeze (28°F) | Mar 19 · Apr 4 · Apr 20 | Oct 21 · Nov 4 · Nov 18 | 214 days | 100% |
Planting calendar for Portsmouth
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 5 |
| 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 15 |
| Summer squash | Sow outdoors | May 3 – Jun 17 |
| Winter squash & pumpkins | Sow outdoors | May 17 – Jun 17 |
| Snap beans | Sow outdoors | May 3 – Aug 7 |
| Sweet corn | Sow outdoors | May 3 – Jul 5 |
| 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 25 – Jul 5 |
| Broccoli | Transplant outdoors (fall) | Jul 25 – Aug 5 |
| Cabbage | Start seeds indoors (spring) | Feb 17 – Mar 17 |
| Cabbage | Transplant outdoors (spring) | Mar 17 – Apr 17 |
| Cabbage | Start seeds indoors (fall) | Jun 15 – Jul 15 |
| Cabbage | Transplant outdoors (fall) | Jul 15 – Aug 15 |
| Leaf lettuce | Sow outdoors (spring) | Mar 17 – Jun 2 |
| Leaf lettuce | Sow outdoors (fall) | Jul 15 – Aug 31 |
| Spinach | Sow outdoors (spring) | Mar 10 – Apr 23 |
| Spinach | Sow outdoors (fall) | Aug 1 – Sep 5 |
| Radishes | Sow outdoors (spring) | Mar 17 – May 7 |
| Radishes | Sow outdoors (fall) | Jul 15 – Sep 15 |
| Kale | Sow outdoors (spring) | Apr 3 – Apr 23 |
| Kale | Sow outdoors (fall) | Jul 8 – Aug 15 |
| Carrots | Sow outdoors (spring) | Apr 17 – Jun 2 |
| Carrots | Sow outdoors (fall) | Jun 15 – Jul 31 |
| Garlic | Plant outdoors (fall) | Oct 15 – Nov 15 |
Where these dates come from
ZIP code 45662 is matched to the NOAA station Portsmouth-Sciotoville, OH, 5.5 km away, at 540 ft elevation (405 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Portsmouth-Sciotoville, OH (used) | 540 ft | Apr 17 | Oct 25 |
| Lucasville, OH | 568 ft | Apr 21 | Oct 24 |
| Warnock 2, KY | 910 ft | Apr 20 | Oct 22 |
| Waverly, OH | 572 ft | Apr 21 | Oct 22 |
Frost dates near Portsmouth
- South Shore, KY 41175 · last Apr 17, first Oct 25
- Wheelersburg, OH 45694 · last Apr 17, first Oct 25
- Lucasville, OH 45699 · last Apr 21, first Oct 24
- Minford, OH 45653 · last Apr 17, first Oct 25
- South Portsmouth, KY 41174 · last Apr 17, first Oct 25
- Mc Dermott, OH 45652 · last Apr 17, first Oct 25
- Scioto Furnace, OH 45677 · last Apr 17, first Oct 25
- Friendship, OH 45630 · last Apr 17, first Oct 25
Frequently asked questions
- When is the last frost in Portsmouth, OH?
- For ZIP code 45662, the average last spring frost (32°F) is April 17, based on NOAA 1991-2020 climate normals for the Portsmouth-Sciotoville, OH weather station. There is a 1-in-10 chance of a frost after May 5.
- When is the first frost in Portsmouth, OH?
- The average first fall frost (32°F) is October 25. 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 45662?
- 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.