Fall in zone 9aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 85131 (Eloy, AZ)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Arizona City, AZ (9 miles away).
- Average last spring frostFeb 2850% chance of a 32°F freeze after this date
- Average first fall frostNov 2150% chance of a 32°F freeze by this date
- Growing season (frost-free)266 daysmedian, 32°F threshold
- USDA hardiness zone9a20 to 25°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
76°F 55°F or warmer
24-hour average · latest 73°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Tucson 11 W (37 mi).
4-inch depth
76°F 55°F or warmer
24-hour average · latest 75°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Tucson 11 W (37 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 85131 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 76°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): not yet. Apply as soil cools toward 70°F (typically September to October).
Fertilizer window
Lawn region: Arid Southwest (low desert). Timing only; always follow the product label.
- Bermudagrass (warm-season): Spring: Several weeks after the lawn is fully green (April–May) (about Apr 15 here, using green-up about 3–4 weeks after your average last frost); Summer: Every 4–6 weeks through mid-August (heaviest feeder of the group); Late: Light, low-nitrogen/high-potassium feeding about 4 weeks before first frost, or skip. Avoid: Heavy late-fall nitrogen (linked to spring dead spot).
- Perennial ryegrass (cool-season): Early fall: September; Late fall: October–November; Overseeded Bermuda: Light feeding once the winter rye is established, if needed. Avoid: Summer feeding.
Plant now
- Arugula: fall sowing Sep 26–Oct 24
- Radish: fall sowing Oct 10–24
- Garlic: fall sowing Oct 10–Nov 7
- Shallot: fall sowing Oct 10–Nov 7
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 21: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Feb 3 |
| 50% (the "average" last frost) | Feb 28 |
| 10% (cautious: only 1 year in 10 freezes later) | Mar 14 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Nov 5 |
| 50% (the "average" first frost) | Nov 21 |
| 90% (late: most years have frozen by now) | Dec 6 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Mar 17 | Nov 12 |
| 32°F (freeze) | Feb 28 | Nov 21 |
| 28°F (hard freeze) | Feb 6 | Dec 4 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 85131
Dates count from your average last spring frost (Feb 28) and first fall frost (Nov 21). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Jan 3–17 | Mar 7–21 (transplant) | Jul 25–Aug 22 (transplant) |
| Pepper (sweet and hot) | Dec 20–Jan 3 | Mar 14–28 (transplant) | Aug 1–22 (transplant) |
| Eggplant | Dec 20–Jan 3 | Mar 14–28 (transplant) | Aug 1–22 (transplant) |
| Tomatillo | Jan 3–17 | Mar 7–21 (transplant) | – |
| Lettuce | Jan 3–17 | Feb 7–28 (transplant) Jan 31–Mar 14 (sow outdoors) | Sep 26–Oct 17 (transplant) Sep 12–Oct 10 (sowing) |
| Spinach | – | Jan 17–Feb 7 (sow outdoors) | Sep 26–Oct 17 (sowing) |
| Kale | Jan 3–17 | Jan 31–Feb 14 (transplant) Jan 31–Feb 14 (sow outdoors) | Aug 29–Sep 26 (transplant) Aug 15–Sep 12 (sowing) |
| Collards | Jan 3–17 | Jan 31–Feb 28 (transplant) Jan 31–Feb 28 (sow outdoors) | Aug 29–Sep 26 (transplant) Aug 15–Sep 12 (sowing) |
| Broccoli | Dec 20–Jan 3 | Jan 31–Feb 14 (transplant) | Aug 15–Sep 12 (transplant) |
| Cabbage | Dec 20–Jan 3 | Jan 31–Feb 14 (transplant) | Aug 15–Sep 12 (transplant) |
| Cauliflower | Dec 20–Jan 3 | Feb 14–28 (transplant) | Aug 15–Sep 12 (transplant) |
| Brussels sprouts | Dec 6–20 | Jan 31–Feb 14 (transplant) | Aug 1–22 (transplant) |
| Kohlrabi | Jan 3–17 | Jan 31–Feb 14 (transplant) Jan 31–Feb 14 (sow outdoors) | Sep 12–26 (sowing) |
| Bok choy / Asian greens | – | Jan 31–Feb 14 (sow outdoors) | Sep 26–Oct 10 (sowing) |
| Arugula | – | Jan 31–Feb 28 (sow outdoors) | Sep 26–Oct 24 (sowing) |
| Mustard greens | – | Jan 31–Feb 21 (sow outdoors) | Sep 26–Oct 10 (sowing) |
| Swiss chard | Jan 17–31 | Feb 14–Mar 7 (transplant) Feb 14–Mar 14 (sow outdoors) | Sep 12–26 (sowing) |
| Beet | – | Jan 31–Feb 28 (sow outdoors) | Sep 12–26 (sowing) |
| Carrot | – | Feb 7–Mar 7 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Radish | – | Jan 24–Mar 7 (sow outdoors) | Oct 10–24 (sowing) |
| Turnip | – | Jan 31–Feb 21 (sow outdoors) | Sep 12–26 (sowing) |
| Parsnip | – | Feb 7–28 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Jan 3–31 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Onion (bulbing) | Dec 6–20 | Jan 17–31 (transplant) | – |
| Green onion / scallion | – | Jan 17–Feb 14 (sow outdoors) | Sep 12–26 (sowing) |
| Leek | Dec 6–20 | Jan 31–Feb 14 (transplant) | – |
| Garlic | – | – | Oct 10–Nov 7 (sowing) |
| Shallot | – | Jan 17–31 (transplant) | Oct 10–Nov 7 (sowing) |
| Potato | – | Jan 31–Feb 14 (transplant) | Aug 1–15 (transplant) |
| Sweet potato | – | Mar 21–Apr 4 (transplant) | – |
| Sweet corn | – | Mar 7–21 (sow outdoors) | – |
| Bean, bush (snap) | – | Mar 7–21 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Bean, pole | – | Mar 7–21 (sow outdoors) | – |
| Lima bean | – | Mar 14–28 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Mar 21–Apr 11 (sow outdoors) | – |
| Cucumber | Jan 31–Feb 7 | Mar 7–21 (transplant) Mar 7–21 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Summer squash / zucchini | Jan 31–Feb 7 | Mar 7–21 (transplant) Mar 7–21 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Winter squash | Jan 31–Feb 7 | Mar 7–21 (transplant) Mar 7–21 (sow outdoors) | – |
| Pumpkin | – | Mar 7–21 (sow outdoors) | – |
| Watermelon | Jan 31–Feb 7 | Mar 14–28 (transplant) Mar 14–28 (sow outdoors) | – |
| Cantaloupe / muskmelon | Jan 31–Feb 7 | Mar 14–28 (transplant) Mar 14–28 (sow outdoors) | – |
| Okra | Jan 17–31 | Mar 14–28 (transplant) Mar 14–28 (sow outdoors) | – |
| Celery | Dec 6–20 | Mar 7–14 (transplant) | – |
| Basil | Jan 17–31 | Mar 7–21 (transplant) Mar 7–21 (sow outdoors) | – |
| Cilantro | – | Feb 14–Mar 14 (sow outdoors) | Sep 26–Oct 10 (sowing) |
| Parsley | Dec 20–Jan 3 | Feb 14–28 (transplant) Feb 7–28 (sow outdoors) | – |
| Dill | – | Feb 28–Mar 14 (sow outdoors) | Sep 26–Oct 10 (sowing) |
| Sunflower | – | Feb 28–Mar 14 (sow outdoors) | – |
| Asparagus (crowns) | – | Jan 31–Feb 14 (transplant) | – |
| Rhubarb (crowns) | – | Jan 31–Feb 14 (transplant) | – |
| Strawberry (plants) | – | Jan 31–Feb 14 (transplant) | Sep 12–Oct 10 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Arizona City, AZ (NOAA GHCN-Daily ID USC00020404), elevation 1,525 ft, 8.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Eloy 4 NE, AZ | 10 mi | Feb 24 | Nov 28 |
| Picacho 8 SE, AZ | 10 mi | Feb 6 | Dec 9 |
| Robson Rch, AZ | 11 mi | Feb 7 | Dec 3 |
The average last-frost dates of these stations span 22 days, a rough guide to local variation. See data sources & methods.
Frost questions for 85131
When is the last frost in 85131?
The average (50% chance) last spring freeze of 32°F for ZIP 85131 is February 28. For a more cautious planting date, use March 14, when only 1 year in 10 still sees a later freeze.
When is the first frost in 85131?
The average first fall freeze is November 21. In 1 year in 10 it comes by November 5.
What hardiness zone is 85131?
ZIP 85131 is in USDA zone 9a (20 to 25°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 85131 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
85123 Eloy 85141 Picacho 85145 Red Rock 85194 Casa Grande 85193 Casa Grande 85122 Casa Grande 85653 Marana 85128 Coolidge
Other ZIP codes in Pinal County
85118 85119 85120 85121 85122 85123 85128 85132 85137 85138 85139 85140 85141 85142 85143 85145 85147 85172 85173 85191 85192 85193 85194 85618 All Pinal County frost dates · Arizona frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
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- Weekly yard to-dos
Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.