Fall in zone 9aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 85191 (Pinal County, 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, Florence, AZ (5 miles away).
- Average last spring frostJan 3050% chance of a 32°F freeze after this date
- Average first fall frostDec 1250% chance of a 32°F freeze by this date
- Growing season (frost-free)319 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 (54 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 (54 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 85191 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 Mar 17 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 3–31
- Lettuce: fall transplant Oct 17–Nov 7
- Spinach: fall sowing Oct 17–Nov 7
- Bok choy / Asian greens: fall sowing Oct 17–31
- Arugula: fall sowing Oct 17–Nov 14
- Mustard greens: fall sowing Oct 17–31
- Cilantro: fall sowing Oct 17–31
- Dill: fall sowing Oct 17–31
- Strawberry (plants): fall transplant Oct 3–31
Coming up in the next 3 weeks
- Brussels sprouts: start seeds indoors Nov 7–21
- Radish: fall sowing Oct 31–Nov 14
- Onion (bulbing): start seeds indoors Nov 7–21
- Leek: start seeds indoors Nov 7–21
- Garlic: fall sowing Oct 31–Nov 28
- Shallot: fall sowing Oct 31–Nov 28
- Celery: start seeds indoors Nov 7–21
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Dec 12: 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) | Dec 27 (prior Dec) |
| 50% (the "average" last frost) | Jan 30 |
| 10% (cautious: only 1 year in 10 freezes later) | Feb 24 |
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 22 |
| 50% (the "average" first frost) | Dec 12 |
| 90% (late: most years have frozen by now) | Jan 12 (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 29 |
| 32°F (freeze) | Jan 30 | Dec 12 |
| 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 85191
Dates count from your average last spring frost (Jan 30) and first fall frost (Dec 12). 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 5–19 | Feb 6–20 (transplant) | Aug 15–Sep 12 (transplant) |
| Pepper (sweet and hot) | Nov 21–Dec 5 | Feb 13–27 (transplant) | Aug 22–Sep 12 (transplant) |
| Eggplant | Nov 21–Dec 5 | Feb 13–27 (transplant) | Aug 22–Sep 12 (transplant) |
| Tomatillo | Dec 5–19 | Feb 6–20 (transplant) | – |
| Lettuce | Dec 5–19 | Jan 9–30 (transplant) Jan 2–Feb 13 (sow outdoors) | Oct 17–Nov 7 (transplant) Oct 3–31 (sowing) |
| Spinach | – | Dec 19–Jan 9 (sow outdoors) | Oct 17–Nov 7 (sowing) |
| Kale | Dec 5–19 | Jan 2–16 (transplant) Jan 2–16 (sow outdoors) | Sep 19–Oct 17 (transplant) Sep 5–Oct 3 (sowing) |
| Collards | Dec 5–19 | Jan 2–30 (transplant) Jan 2–30 (sow outdoors) | Sep 19–Oct 17 (transplant) Sep 5–Oct 3 (sowing) |
| Broccoli | Nov 21–Dec 5 | Jan 2–16 (transplant) | Sep 5–Oct 3 (transplant) |
| Cabbage | Nov 21–Dec 5 | Jan 2–16 (transplant) | Sep 5–Oct 3 (transplant) |
| Cauliflower | Nov 21–Dec 5 | Jan 16–30 (transplant) | Sep 5–Oct 3 (transplant) |
| Brussels sprouts | Nov 7–21 | Jan 2–16 (transplant) | Aug 22–Sep 12 (transplant) |
| Kohlrabi | Dec 5–19 | Jan 2–16 (transplant) Jan 2–16 (sow outdoors) | Oct 3–17 (sowing) |
| Bok choy / Asian greens | – | Jan 2–16 (sow outdoors) | Oct 17–31 (sowing) |
| Arugula | – | Jan 2–30 (sow outdoors) | Oct 17–Nov 14 (sowing) |
| Mustard greens | – | Jan 2–23 (sow outdoors) | Oct 17–31 (sowing) |
| Swiss chard | Dec 19–Jan 2 | Jan 16–Feb 6 (transplant) Jan 16–Feb 13 (sow outdoors) | Oct 3–17 (sowing) |
| Beet | – | Jan 2–30 (sow outdoors) | Oct 3–17 (sowing) |
| Carrot | – | Jan 9–Feb 6 (sow outdoors) | Sep 19–Oct 3 (sowing) |
| Radish | – | Dec 26–Feb 6 (sow outdoors) | Oct 31–Nov 14 (sowing) |
| Turnip | – | Jan 2–23 (sow outdoors) | Oct 3–17 (sowing) |
| Parsnip | – | Jan 9–30 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Dec 5–Jan 2 (sow outdoors) | Sep 19–Oct 3 (sowing) |
| Onion (bulbing) | Nov 7–21 | Dec 19–Jan 2 (transplant) | – |
| Green onion / scallion | – | Dec 19–Jan 16 (sow outdoors) | Oct 3–17 (sowing) |
| Leek | Nov 7–21 | Jan 2–16 (transplant) | – |
| Garlic | – | – | Oct 31–Nov 28 (sowing) |
| Shallot | – | Dec 19–Jan 2 (transplant) | Oct 31–Nov 28 (sowing) |
| Potato | – | Jan 2–16 (transplant) | Aug 22–Sep 5 (transplant) |
| Sweet potato | – | Feb 20–Mar 6 (transplant) | – |
| Sweet corn | – | Feb 6–20 (sow outdoors) | – |
| Bean, bush (snap) | – | Feb 6–20 (sow outdoors) | Sep 19–Oct 3 (sowing) |
| Bean, pole | – | Feb 6–20 (sow outdoors) | – |
| Lima bean | – | Feb 13–27 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Feb 20–Mar 13 (sow outdoors) | – |
| Cucumber | Jan 2–9 | Feb 6–20 (transplant) Feb 6–20 (sow outdoors) | Sep 19–Oct 3 (sowing) |
| Summer squash / zucchini | Jan 2–9 | Feb 6–20 (transplant) Feb 6–20 (sow outdoors) | Sep 19–Oct 3 (sowing) |
| Winter squash | Jan 2–9 | Feb 6–20 (transplant) Feb 6–20 (sow outdoors) | – |
| Pumpkin | – | Feb 6–20 (sow outdoors) | – |
| Watermelon | Jan 2–9 | Feb 13–27 (transplant) Feb 13–27 (sow outdoors) | – |
| Cantaloupe / muskmelon | Jan 2–9 | Feb 13–27 (transplant) Feb 13–27 (sow outdoors) | – |
| Okra | Dec 19–Jan 2 | Feb 13–27 (transplant) Feb 13–27 (sow outdoors) | – |
| Celery | Nov 7–21 | Feb 6–13 (transplant) | – |
| Basil | Dec 19–Jan 2 | Feb 6–20 (transplant) Feb 6–20 (sow outdoors) | – |
| Cilantro | – | Jan 16–Feb 13 (sow outdoors) | Oct 17–31 (sowing) |
| Parsley | Nov 21–Dec 5 | Jan 16–30 (transplant) Jan 9–30 (sow outdoors) | – |
| Dill | – | Jan 30–Feb 13 (sow outdoors) | Oct 17–31 (sowing) |
| Sunflower | – | Jan 30–Feb 13 (sow outdoors) | – |
| Asparagus (crowns) | – | Jan 2–16 (transplant) | – |
| Rhubarb (crowns) | – | Jan 2–16 (transplant) | – |
| Strawberry (plants) | – | Jan 2–16 (transplant) | Oct 3–31 (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: Florence, AZ (NOAA GHCN-Daily ID USC00023027), elevation 1,400 ft, 4.9 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Casa Grande Nm, AZ | 5 mi | Feb 17 | Nov 29 |
| Eloy 4 NE, AZ | 15 mi | Feb 24 | Nov 28 |
| Robson Rch, AZ | 16 mi | Feb 7 | Dec 3 |
The average last-frost dates of these stations span 25 days, a rough guide to local variation. See data sources & methods.
Frost questions for 85191
When is the last frost in 85191?
The average (50% chance) last spring freeze of 32°F for ZIP 85191 is January 30. For a more cautious planting date, use February 24, when only 1 year in 10 still sees a later freeze.
When is the first frost in 85191?
The average first fall freeze is December 12. In 1 year in 10 it comes by November 22.
What hardiness zone is 85191?
ZIP 85191 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 85191 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
85128 Coolidge 85194 Casa Grande 85143 San Tan Valley 85132 Florence 85147 Sacaton 85122 Casa Grande 85140 San Tan Valley 85142 Queen Creek
Other ZIP codes in Pinal County
85118 85119 85120 85121 85122 85123 85128 85131 85132 85137 85138 85139 85140 85141 85142 85143 85145 85147 85172 85173 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.