Frost dates for 85257Scottsdale, AZ
The average last spring frost in Scottsdale is February 13 and the average first fall frost is December 5, giving a typical growing season of about 298 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 13
- Average first fall frost
- Dec 5
- Growing season
- 298 days
Safer after Mar 9 (1-in-10 risk)
Possible by Nov 18 (1-in-10 risk)
First frost typically in 40 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) | Feb 14 · Mar 8 · Apr 7 | Nov 7 · Nov 26 · Dec 9 | 259 days | 100% |
| Frost / freeze (32°F) | Jan 12 · Feb 13 · Mar 9 | Nov 18 · Dec 5 · Dec 24 | 298 days | 100% |
| Hard freeze (28°F) | Dec 19 · Jan 16 · Feb 19 | Nov 27 · Dec 19 · Jan 19 | 337 days | 87% |
Planting calendar for Scottsdale
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 | Jan 13 – Mar 21 |
| Tomatoes | Transplant outdoors | Mar 1 – Aug 15 |
| Peppers | Start seeds indoors | Jan 13 – Feb 13 |
| Peppers | Transplant outdoors | Mar 15 – Apr 15 |
| Eggplant | Start seeds indoors | Jan 30 – Feb 28 |
| Eggplant | Transplant outdoors | Mar 15 – Apr 15 |
| Cucumbers | Sow outdoors | Mar 15 – Aug 25 |
| Summer squash | Sow outdoors | Mar 1 – Apr 15 |
| Winter squash & pumpkins | Sow outdoors | Mar 15 – Apr 15 |
| Snap beans | Sow outdoors | Mar 1 – Sep 17 |
| Sweet corn | Sow outdoors | Mar 1 – Aug 15 |
| Watermelon & cantaloupe | Sow outdoors | Mar 15 – Apr 15 |
| Okra | Sow outdoors | Mar 8 – Mar 31 |
| Peas | Sow outdoors (spring) | Jan 13 – Feb 28 |
| Potatoes | Plant outdoors (spring) | Jan 13 – Mar 15 |
| Onions | Start seeds indoors (spring) | Dec 2 – Dec 29 |
| Onions | Transplant outdoors (spring) | Jan 30 – Feb 28 |
| Broccoli | Start seeds indoors (spring) | Dec 26 – Jan 29 |
| Broccoli | Transplant outdoors (spring) | Jan 30 – Feb 28 |
| Broccoli | Start seeds indoors (fall) | Aug 5 – Aug 15 |
| Broccoli | Transplant outdoors (fall) | Sep 4 – Sep 15 |
| Cabbage | Start seeds indoors (spring) | Dec 16 – Jan 13 |
| Cabbage | Transplant outdoors (spring) | Jan 13 – Feb 13 |
| Cabbage | Start seeds indoors (fall) | Jul 26 – Aug 25 |
| Cabbage | Transplant outdoors (fall) | Aug 25 – Sep 25 |
| Leaf lettuce | Sow outdoors (spring) | Jan 13 – Mar 31 |
| Leaf lettuce | Sow outdoors (fall) | Aug 25 – Oct 11 |
| Spinach | Sow outdoors (spring) | Jan 6 – Feb 19 |
| Spinach | Sow outdoors (fall) | Sep 11 – Oct 16 |
| Radishes | Sow outdoors (spring) | Jan 13 – Mar 5 |
| Radishes | Sow outdoors (fall) | Aug 25 – Oct 26 |
| Kale | Sow outdoors (spring) | Jan 30 – Feb 19 |
| Kale | Sow outdoors (fall) | Aug 18 – Sep 25 |
| Carrots | Sow outdoors (spring) | Feb 13 – Mar 31 |
| Carrots | Sow outdoors (fall) | Jul 26 – Sep 10 |
| Garlic | Plant outdoors (fall) | Nov 25 – Dec 26 |
Where these dates come from
ZIP code 85257 is matched to the NOAA station Tempe Asu, AZ, 4.6 km away, at 1,167 ft elevation (37 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Tempe Asu, AZ (used) | 1,167 ft | Feb 13 | Dec 5 |
| Phoenix Sky Harbor Intl Ap, AZ | 1,107 ft | Jan 5 | Jan 3 |
| South Phoenix, AZ | 1,155 ft | Jan 21 | Dec 16 |
| Scottsdale Muni Ap, AZ | 1,473 ft | Jan 6 | Dec 26 |
Frost dates near Scottsdale
- Tempe, AZ 85288 · last Feb 13, first Dec 5
- Scottsdale, AZ 85251 · last Feb 13, first Dec 5
- Mesa, AZ 85211 · last Feb 13, first Dec 5
- Phoenix, AZ 85018 · last Feb 13, first Dec 5
- Paradise Valley, AZ 85253 · last Jan 6, first Dec 26
- Chandler, AZ 85224 · last Feb 13, first Dec 5
- Gilbert, AZ 85299 · last Feb 13, first Dec 5
- Fountain Hills, AZ 85268 · last Jan 6, first Dec 28
Frequently asked questions
- When is the last frost in Scottsdale, AZ?
- For ZIP code 85257, the average last spring frost (32°F) is February 13, based on NOAA 1991-2020 climate normals for the Tempe Asu, AZ weather station. There is a 1-in-10 chance of a frost after March 9.
- When is the first frost in Scottsdale, AZ?
- The average first fall frost (32°F) is December 5. There is a 1-in-10 chance of frost by November 18, so tender plants are at risk from that point on.
- How long is the growing season in 85257?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 298 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.