Frost dates for 85536Fort Thomas, AZ
The average last spring frost in Fort Thomas is April 1 and the average first fall frost is November 6, giving a typical growing season of about 217 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 1
- Average first fall frost
- Nov 6
- Growing season
- 217 days
Safer after Apr 18 (1-in-10 risk)
Possible by Oct 21 (1-in-10 risk)
First frost typically in 10 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 2 · Apr 17 · May 4 | Oct 15 · Oct 29 · Nov 10 | 193 days | 100% |
| Frost / freeze (32°F) | Mar 15 · Apr 1 · Apr 18 | Oct 21 · Nov 6 · Nov 19 | 217 days | 100% |
| Hard freeze (28°F) | Feb 24 · Mar 13 · Apr 3 | Oct 30 · Nov 16 · Nov 29 | 244 days | 100% |
Planting calendar for Fort Thomas
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 1 – May 7 |
| Tomatoes | Transplant outdoors | Apr 17 – Jul 17 |
| Peppers | Start seeds indoors | Mar 1 – Apr 1 |
| Peppers | Transplant outdoors | May 1 – Jun 1 |
| Eggplant | Start seeds indoors | Mar 18 – Apr 16 |
| Eggplant | Transplant outdoors | May 1 – Jun 1 |
| Cucumbers | Sow outdoors | May 1 – Jul 27 |
| Summer squash | Sow outdoors | Apr 17 – Jun 1 |
| Winter squash & pumpkins | Sow outdoors | May 1 – Jun 1 |
| Snap beans | Sow outdoors | Apr 17 – Aug 19 |
| Sweet corn | Sow outdoors | Apr 17 – Jul 17 |
| Watermelon & cantaloupe | Sow outdoors | May 1 – Jun 1 |
| Okra | Sow outdoors | Apr 24 – May 17 |
| Peas | Sow outdoors (spring) | Mar 1 – Apr 16 |
| Potatoes | Plant outdoors (spring) | Mar 1 – May 1 |
| Onions | Start seeds indoors (spring) | Jan 18 – Feb 14 |
| Onions | Transplant outdoors (spring) | Mar 18 – Apr 16 |
| Broccoli | Start seeds indoors (spring) | Feb 11 – Mar 17 |
| Broccoli | Transplant outdoors (spring) | Mar 18 – Apr 16 |
| Broccoli | Start seeds indoors (fall) | Jul 7 – Jul 17 |
| Broccoli | Transplant outdoors (fall) | Aug 6 – Aug 17 |
| Cabbage | Start seeds indoors (spring) | Feb 1 – Mar 1 |
| Cabbage | Transplant outdoors (spring) | Mar 1 – Apr 1 |
| Cabbage | Start seeds indoors (fall) | Jun 27 – Jul 27 |
| Cabbage | Transplant outdoors (fall) | Jul 27 – Aug 27 |
| Leaf lettuce | Sow outdoors (spring) | Mar 1 – May 17 |
| Leaf lettuce | Sow outdoors (fall) | Jul 27 – Sep 12 |
| Spinach | Sow outdoors (spring) | Feb 22 – Apr 7 |
| Spinach | Sow outdoors (fall) | Aug 13 – Sep 17 |
| Radishes | Sow outdoors (spring) | Mar 1 – Apr 21 |
| Radishes | Sow outdoors (fall) | Jul 27 – Sep 27 |
| Kale | Sow outdoors (spring) | Mar 18 – Apr 7 |
| Kale | Sow outdoors (fall) | Jul 20 – Aug 27 |
| Carrots | Sow outdoors (spring) | Apr 1 – May 17 |
| Carrots | Sow outdoors (fall) | Jun 27 – Aug 12 |
| Garlic | Plant outdoors (fall) | Oct 27 – Nov 27 |
Where these dates come from
ZIP code 85536 is matched to the NOAA station Ft Thomas 2 Sw, AZ, 3 km away, at 2,835 ft elevation (73 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ft Thomas 2 Sw, AZ (used) | 2,835 ft | Apr 1 | Nov 6 |
| Safford Ag Ctr, AZ | 2,954 ft | Mar 25 | Nov 9 |
| Safford Muni Ap, AZ | 3,176 ft | Mar 8 | Nov 20 |
| Black Rvr Pumps, AZ | 6,065 ft | May 16 | Oct 13 |
Frost dates near Fort Thomas
- Eden, AZ 85535 · last Apr 1, first Nov 6
- Bylas, AZ 85530 · last Apr 1, first Nov 6
- Pima, AZ 85543 · last Apr 1, first Nov 6
- Central, AZ 85531 · last Mar 25, first Nov 9
- Thatcher, AZ 85552 · last Mar 25, first Nov 9
- Safford, AZ 85548 · last Mar 25, first Nov 9
- Solomon, AZ 85551 · last Mar 25, first Nov 9
- Peridot, AZ 85542 · last Mar 13, first Nov 19
Frequently asked questions
- When is the last frost in Fort Thomas, AZ?
- For ZIP code 85536, the average last spring frost (32°F) is April 1, based on NOAA 1991-2020 climate normals for the Ft Thomas 2 Sw, AZ weather station. There is a 1-in-10 chance of a frost after April 18.
- When is the first frost in Fort Thomas, AZ?
- The average first fall frost (32°F) is November 6. There is a 1-in-10 chance of frost by October 21, so tender plants are at risk from that point on.
- How long is the growing season in 85536?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 217 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.