Fall in zone 9bPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 85140 (San Tan Valley, 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, Chandler Heights, AZ (11 miles away).
- Average last spring frostFeb 150% chance of a 32°F freeze after this date
- Average first fall frostDec 1150% chance of a 32°F freeze by this date
- Growing season (frost-free)315 daysmedian, 32°F threshold
- USDA hardiness zone9b25 to 30°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
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
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 85140 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring late January to February; fall 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 Mar 19 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
- Lettuce: fall sowing Oct 2–30
- Lettuce: fall transplant Oct 16–Nov 6
- Spinach: fall sowing Oct 16–Nov 6
- Bok choy / Asian greens: fall sowing Oct 16–30
- Arugula: fall sowing Oct 16–Nov 13
- Mustard greens: fall sowing Oct 16–30
- Cilantro: fall sowing Oct 16–30
- Dill: fall sowing Oct 16–30
- Strawberry (plants): fall transplant Oct 2–30
Coming up in the next 3 weeks
- Radish: fall sowing Oct 30–Nov 13
- Garlic: fall sowing Oct 30–Nov 27
- Shallot: fall sowing Oct 30–Nov 27
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Dec 11: 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) | Jan 2 |
| 50% (the "average" last frost) | Feb 1 |
| 10% (cautious: only 1 year in 10 freezes later) | Feb 27 |
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 23 |
| 50% (the "average" first frost) | Dec 11 |
| 90% (late: most years have frozen by now) | Jan 1 (next year) |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Feb 21 | Nov 28 |
| 32°F (freeze) | Feb 1 | Dec 11 |
| 28°F (hard freeze) | Jan 8 | Dec 26 |
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 85140
Dates count from your average last spring frost (Feb 1) and first fall frost (Dec 11). 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 | Dec 7–21 | Feb 8–22 (transplant) | Aug 14–Sep 11 (transplant) |
| Pepper (sweet and hot) | Nov 23–Dec 7 | Feb 15–Mar 1 (transplant) | Aug 21–Sep 11 (transplant) |
| Eggplant | Nov 23–Dec 7 | Feb 15–Mar 1 (transplant) | Aug 21–Sep 11 (transplant) |
| Tomatillo | Dec 7–21 | Feb 8–22 (transplant) | – |
| Lettuce | Dec 7–21 | Jan 11–Feb 1 (transplant) Jan 4–Feb 15 (sow outdoors) | Oct 16–Nov 6 (transplant) Oct 2–30 (sowing) |
| Spinach | – | Dec 21–Jan 11 (sow outdoors) | Oct 16–Nov 6 (sowing) |
| Kale | Dec 7–21 | Jan 4–18 (transplant) Jan 4–18 (sow outdoors) | Sep 18–Oct 16 (transplant) Sep 4–Oct 2 (sowing) |
| Collards | Dec 7–21 | Jan 4–Feb 1 (transplant) Jan 4–Feb 1 (sow outdoors) | Sep 18–Oct 16 (transplant) Sep 4–Oct 2 (sowing) |
| Broccoli | Nov 23–Dec 7 | Jan 4–18 (transplant) | Sep 4–Oct 2 (transplant) |
| Cabbage | Nov 23–Dec 7 | Jan 4–18 (transplant) | Sep 4–Oct 2 (transplant) |
| Cauliflower | Nov 23–Dec 7 | Jan 18–Feb 1 (transplant) | Sep 4–Oct 2 (transplant) |
| Brussels sprouts | Nov 9–23 | Jan 4–18 (transplant) | Aug 21–Sep 11 (transplant) |
| Kohlrabi | Dec 7–21 | Jan 4–18 (transplant) Jan 4–18 (sow outdoors) | Oct 2–16 (sowing) |
| Bok choy / Asian greens | – | Jan 4–18 (sow outdoors) | Oct 16–30 (sowing) |
| Arugula | – | Jan 4–Feb 1 (sow outdoors) | Oct 16–Nov 13 (sowing) |
| Mustard greens | – | Jan 4–25 (sow outdoors) | Oct 16–30 (sowing) |
| Swiss chard | Dec 21–Jan 4 | Jan 18–Feb 8 (transplant) Jan 18–Feb 15 (sow outdoors) | Oct 2–16 (sowing) |
| Beet | – | Jan 4–Feb 1 (sow outdoors) | Oct 2–16 (sowing) |
| Carrot | – | Jan 11–Feb 8 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Radish | – | Dec 28–Feb 8 (sow outdoors) | Oct 30–Nov 13 (sowing) |
| Turnip | – | Jan 4–25 (sow outdoors) | Oct 2–16 (sowing) |
| Parsnip | – | Jan 11–Feb 1 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Dec 7–Jan 4 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Onion (bulbing) | Nov 9–23 | Dec 21–Jan 4 (transplant) | – |
| Green onion / scallion | – | Dec 21–Jan 18 (sow outdoors) | Oct 2–16 (sowing) |
| Leek | Nov 9–23 | Jan 4–18 (transplant) | – |
| Garlic | – | – | Oct 30–Nov 27 (sowing) |
| Shallot | – | Dec 21–Jan 4 (transplant) | Oct 30–Nov 27 (sowing) |
| Potato | – | Jan 4–18 (transplant) | Aug 21–Sep 4 (transplant) |
| Sweet potato | – | Feb 22–Mar 8 (transplant) | – |
| Sweet corn | – | Feb 8–22 (sow outdoors) | – |
| Bean, bush (snap) | – | Feb 8–22 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Bean, pole | – | Feb 8–22 (sow outdoors) | – |
| Lima bean | – | Feb 15–Mar 1 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Feb 22–Mar 15 (sow outdoors) | – |
| Cucumber | Jan 4–11 | Feb 8–22 (transplant) Feb 8–22 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Summer squash / zucchini | Jan 4–11 | Feb 8–22 (transplant) Feb 8–22 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Winter squash | Jan 4–11 | Feb 8–22 (transplant) Feb 8–22 (sow outdoors) | – |
| Pumpkin | – | Feb 8–22 (sow outdoors) | – |
| Watermelon | Jan 4–11 | Feb 15–Mar 1 (transplant) Feb 15–Mar 1 (sow outdoors) | – |
| Cantaloupe / muskmelon | Jan 4–11 | Feb 15–Mar 1 (transplant) Feb 15–Mar 1 (sow outdoors) | – |
| Okra | Dec 21–Jan 4 | Feb 15–Mar 1 (transplant) Feb 15–Mar 1 (sow outdoors) | – |
| Celery | Nov 9–23 | Feb 8–15 (transplant) | – |
| Basil | Dec 21–Jan 4 | Feb 8–22 (transplant) Feb 8–22 (sow outdoors) | – |
| Cilantro | – | Jan 18–Feb 15 (sow outdoors) | Oct 16–30 (sowing) |
| Parsley | Nov 23–Dec 7 | Jan 18–Feb 1 (transplant) Jan 11–Feb 1 (sow outdoors) | – |
| Dill | – | Feb 1–15 (sow outdoors) | Oct 16–30 (sowing) |
| Sunflower | – | Feb 1–15 (sow outdoors) | – |
| Asparagus (crowns) | – | Jan 4–18 (transplant) | – |
| Rhubarb (crowns) | – | Jan 4–18 (transplant) | – |
| Strawberry (plants) | – | Jan 4–18 (transplant) | Oct 2–30 (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: Chandler Heights, AZ (NOAA GHCN-Daily ID USC00021514), elevation 1,425 ft, 11.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Apache Junction 5 NE, AZ | 15 mi | Feb 11 | Dec 10 |
| E Mesa, AZ | 15 mi | Feb 1 | Dec 10 |
| Florence, AZ | 16 mi | Jan 30 | Dec 12 |
The average last-frost dates of these stations span 12 days, a rough guide to local variation. See data sources & methods.
Frost questions for 85140
When is the last frost in 85140?
The average (50% chance) last spring freeze of 32°F for ZIP 85140 is February 1. For a more cautious planting date, use February 27, when only 1 year in 10 still sees a later freeze.
When is the first frost in 85140?
The average first fall freeze is December 11. In 1 year in 10 it comes by November 23.
What hardiness zone is 85140?
ZIP 85140 is in USDA zone 9b (25 to 30°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 85140 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
85143 San Tan Valley 85212 Mesa 85119 Apache Junction 85120 Apache Junction 85118 Gold Canyon 85142 Queen Creek 85209 Mesa 85208 Mesa
Other ZIP codes in Pinal County
85118 85119 85120 85121 85122 85123 85128 85131 85132 85137 85138 85139 85141 85142 85143 85145 85147 85172 85173 85191 85192 85193 85194 85618 All Pinal County frost dates · Arizona frost dates
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- Freeze alerts
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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.