Frost dates for 86331Jerome, AZ
The average last spring frost in Jerome is March 26 and the average first fall frost is November 25, giving a typical growing season of about 242 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 26
- Average first fall frost
- Nov 25
- Growing season
- 242 days
Safer after Apr 19 (1-in-10 risk)
Possible by Nov 4 (1-in-10 risk)
First frost typically in 29 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) | Mar 21 · Apr 13 · May 5 | Oct 24 · Nov 12 · Nov 29 | 212 days | 100% |
| Frost / freeze (32°F) | Feb 28 · Mar 26 · Apr 19 | Nov 4 · Nov 25 · Dec 10 | 242 days | 100% |
| Hard freeze (28°F) | Jan 27 · Mar 1 · Apr 4 | Nov 17 · Dec 6 · Dec 26 | 277 days | 100% |
Planting calendar for Jerome
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 | Feb 23 – May 1 |
| Tomatoes | Transplant outdoors | Apr 11 – Aug 5 |
| Peppers | Start seeds indoors | Feb 23 – Mar 26 |
| Peppers | Transplant outdoors | Apr 25 – May 26 |
| Eggplant | Start seeds indoors | Mar 12 – Apr 10 |
| Eggplant | Transplant outdoors | Apr 25 – May 26 |
| Cucumbers | Sow outdoors | Apr 25 – Aug 15 |
| Summer squash | Sow outdoors | Apr 11 – May 26 |
| Winter squash & pumpkins | Sow outdoors | Apr 25 – May 26 |
| Snap beans | Sow outdoors | Apr 11 – Sep 7 |
| Sweet corn | Sow outdoors | Apr 11 – Aug 5 |
| Watermelon & cantaloupe | Sow outdoors | Apr 25 – May 26 |
| Okra | Sow outdoors | Apr 18 – May 11 |
| Peas | Sow outdoors (spring) | Feb 23 – Apr 10 |
| Potatoes | Plant outdoors (spring) | Feb 23 – Apr 25 |
| Onions | Start seeds indoors (spring) | Jan 12 – Feb 8 |
| Onions | Transplant outdoors (spring) | Mar 12 – Apr 10 |
| Broccoli | Start seeds indoors (spring) | Feb 5 – Mar 11 |
| Broccoli | Transplant outdoors (spring) | Mar 12 – Apr 10 |
| Broccoli | Start seeds indoors (fall) | Jul 26 – Aug 5 |
| Broccoli | Transplant outdoors (fall) | Aug 25 – Sep 5 |
| Cabbage | Start seeds indoors (spring) | Jan 26 – Feb 23 |
| Cabbage | Transplant outdoors (spring) | Feb 23 – Mar 26 |
| Cabbage | Start seeds indoors (fall) | Jul 16 – Aug 15 |
| Cabbage | Transplant outdoors (fall) | Aug 15 – Sep 15 |
| Leaf lettuce | Sow outdoors (spring) | Feb 23 – May 11 |
| Leaf lettuce | Sow outdoors (fall) | Aug 15 – Oct 1 |
| Spinach | Sow outdoors (spring) | Feb 16 – Apr 1 |
| Spinach | Sow outdoors (fall) | Sep 1 – Oct 6 |
| Radishes | Sow outdoors (spring) | Feb 23 – Apr 15 |
| Radishes | Sow outdoors (fall) | Aug 15 – Oct 16 |
| Kale | Sow outdoors (spring) | Mar 12 – Apr 1 |
| Kale | Sow outdoors (fall) | Aug 8 – Sep 15 |
| Carrots | Sow outdoors (spring) | Mar 26 – May 11 |
| Carrots | Sow outdoors (fall) | Jul 16 – Aug 31 |
| Garlic | Plant outdoors (fall) | Nov 15 – Dec 16 |
Where these dates come from
ZIP code 86331 is matched to the NOAA station Jerome, AZ, 0.5 km away, at 4,950 ft elevation (150 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Jerome, AZ (used) | 4,950 ft | Mar 26 | Nov 25 |
| Tuzigoot, AZ | 3,470 ft | Mar 30 | Nov 10 |
| Montezuma Castle Nm, AZ | 3,180 ft | Apr 16 | Oct 30 |
| Prescott Love Fld, AZ | 5,042 ft | Apr 20 | Oct 27 |
Frost dates near Jerome
- Clarkdale, AZ 86324 · last Mar 30, first Nov 10
- Cottonwood, AZ 86326 · last Mar 30, first Nov 10
- Prescott Valley, AZ 86315 · last Apr 30, first Oct 20
- Cornville, AZ 86325 · last Mar 30, first Nov 10
- Prescott, AZ 86313 · last Apr 27, first Oct 24
- Sedona, AZ 86340 · last Apr 27, first Oct 24
- Dewey, AZ 86327 · last Apr 27, first Oct 24
- Humboldt, AZ 86329 · last Apr 27, first Oct 24
Frequently asked questions
- When is the last frost in Jerome, AZ?
- For ZIP code 86331, the average last spring frost (32°F) is March 26, based on NOAA 1991-2020 climate normals for the Jerome, AZ weather station. There is a 1-in-10 chance of a frost after April 19.
- When is the first frost in Jerome, AZ?
- The average first fall frost (32°F) is November 25. There is a 1-in-10 chance of frost by November 4, so tender plants are at risk from that point on.
- How long is the growing season in 86331?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 242 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.