Frost dates for 86305Prescott, AZ
The average last spring frost in Prescott is May 24 and the average first fall frost is October 7, giving a typical growing season of about 135 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 24
- Average first fall frost
- Oct 7
- Growing season
- 135 days
Safer after Jun 11 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 210 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) | May 24 · Jun 8 · Jun 26 | Sep 16 · Sep 29 · Oct 10 | 109 days | 100% |
| Frost / freeze (32°F) | May 7 · May 24 · Jun 11 | Sep 27 · Oct 7 · Oct 23 | 135 days | 100% |
| Hard freeze (28°F) | Apr 18 · May 6 · May 27 | Oct 4 · Oct 18 · Nov 4 | 164 days | 100% |
Planting calendar for Prescott
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 | Apr 23 – Jun 29 |
| Tomatoes | Transplant outdoors | Jun 9 – Jun 17 |
| Peppers | Start seeds indoors | Apr 23 – May 24 |
| Peppers | Transplant outdoors | Jun 23 – Jul 24 |
| Eggplant | Start seeds indoors | May 10 – Jun 8 |
| Eggplant | Transplant outdoors | Jun 23 – Jul 24 |
| Cucumbers | Sow outdoors | Jun 23 – Jun 27 |
| Summer squash | Sow outdoors | Jun 9 – Jul 24 |
| Winter squash & pumpkins | Sow outdoors | Jun 23 – Jul 24 |
| Snap beans | Sow outdoors | Jun 9 – Jul 20 |
| Sweet corn | Sow outdoors | Jun 9 – Jun 17 |
| Watermelon & cantaloupe | Sow outdoors | Jun 23 – Jul 24 |
| Okra | Sow outdoors | Jun 16 – Jul 9 |
| Peas | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Potatoes | Plant outdoors (spring) | Apr 23 – Jun 23 |
| Onions | Start seeds indoors (spring) | Mar 12 – Apr 8 |
| Onions | Transplant outdoors (spring) | May 10 – Jun 8 |
| Broccoli | Start seeds indoors (spring) | Apr 5 – May 9 |
| Broccoli | Transplant outdoors (spring) | May 10 – Jun 8 |
| Broccoli | Start seeds indoors (fall) | Jun 7 – Jun 17 |
| Broccoli | Transplant outdoors (fall) | Jul 7 – Jul 18 |
| Cabbage | Start seeds indoors (spring) | Mar 26 – Apr 23 |
| Cabbage | Transplant outdoors (spring) | Apr 23 – May 24 |
| Cabbage | Start seeds indoors (fall) | May 28 – Jun 27 |
| Cabbage | Transplant outdoors (fall) | Jun 27 – Jul 28 |
| Leaf lettuce | Sow outdoors (spring) | Apr 23 – Jul 9 |
| Leaf lettuce | Sow outdoors (fall) | Jun 27 – Aug 13 |
| Spinach | Sow outdoors (spring) | Apr 16 – May 30 |
| Spinach | Sow outdoors (fall) | Jul 14 – Aug 18 |
| Radishes | Sow outdoors (spring) | Apr 23 – Jun 13 |
| Radishes | Sow outdoors (fall) | Jun 27 – Aug 28 |
| Kale | Sow outdoors (spring) | May 10 – May 30 |
| Kale | Sow outdoors (fall) | Jun 20 – Jul 28 |
| Carrots | Sow outdoors (spring) | May 24 – Jul 9 |
| Carrots | Sow outdoors (fall) | May 28 – Jul 13 |
| Garlic | Plant outdoors (fall) | Sep 27 – Oct 28 |
Where these dates come from
ZIP code 86305 is matched to the NOAA station Walnut Creek, AZ, 18.2 km away, at 5,090 ft elevation (976 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Walnut Creek, AZ (used) | 5,090 ft | May 24 | Oct 7 |
| Bagdad, AZ | 3,935 ft | Apr 7 | Nov 12 |
| Chino Valley, AZ | 4,750 ft | Apr 27 | Oct 24 |
| Prescott Love Fld, AZ | 5,042 ft | Apr 20 | Oct 27 |
Frost dates near Prescott
- Bagdad, AZ 86321 · last Apr 7, first Nov 12
- Kirkland, AZ 86332 · last Apr 7, first Nov 12
- Skull Valley, AZ 86338 · last Apr 27, first Oct 24
- Chino Valley, AZ 86323 · last Apr 27, first Oct 24
- Paulden, AZ 86334 · last May 24, first Oct 7
- Prescott, AZ 86304 · last Apr 30, first Oct 20
- Sedona, AZ 86340 · last Apr 27, first Oct 24
- Seligman, AZ 86337 · last May 10, first Oct 15
Frequently asked questions
- When is the last frost in Prescott, AZ?
- For ZIP code 86305, the average last spring frost (32°F) is May 24, based on NOAA 1991-2020 climate normals for the Walnut Creek, AZ weather station. There is a 1-in-10 chance of a frost after June 11.
- When is the first frost in Prescott, AZ?
- The average first fall frost (32°F) is October 7. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 86305?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 135 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.