USDA Hardiness Zone 9a
Frost Dates for 85131 — Eloy, Arizona
Averages from Arizona City, Az US, the nearest reporting station, 8.1 miles away.
Plant tender crops after February 28, and expect the first autumn freeze around November 21. That leaves about 266 frost-free days.
- Last spring frost
- February 28
- First fall frost
- November 21
- Growing season
- 266 days
- Hardiness zone
- 9a
50% probability
50% probability
frost-free
20 to 25°F annual low
Planting calendar for 85131
| When | What to do |
|---|---|
| December 20 – January 3 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| January 3 – January 17 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| January 31 – February 14 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| February 28 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by August 29 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by November 7 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| November 21 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after February 28 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Eloy, Arizona are past their last freeze. Harvest before November 21, which leaves roughly 266 frost-free days.
ZIP 85131 sits in USDA hardiness zone 9a, meaning the average coldest night of the year falls between 20 to 25°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.