Fall in zone 9bPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 85173 (Superior, 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, Superior, AZ (3 miles away).
Freezes are uncommon here
NOAA's normals for this station show a 32°F night in about 77% of years (about 3 freezing night(s) a year on average). The dates below describe freeze timing for the station's record; in many years there may be no 32°F freeze at all.
- Average last spring frostJan 1850% chance of a 32°F freeze after this date
- Average first fall frostDec 2850% chance of a 32°F freeze by this date
- Growing season (frost-free)342 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
Freezes are uncommon here, so frost-based timing is rough. Local extension calendars for frost-free areas use months.
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 85173 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 5 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
- Kale: fall sowing Sep 21–Oct 19
- Kale: fall transplant Oct 5–Nov 2
- Collards: fall sowing Sep 21–Oct 19
- Collards: fall transplant Oct 5–Nov 2
- Broccoli: fall transplant Sep 21–Oct 19
- Cabbage: fall transplant Sep 21–Oct 19
- Cauliflower: fall transplant Sep 21–Oct 19
- Carrot: fall sowing Oct 5–19
- Pea (garden, snap, snow): fall sowing Oct 5–19
- Bean, bush (snap): fall sowing Oct 5–19
- Cucumber: fall sowing Oct 5–19
- Summer squash / zucchini: fall sowing Oct 5–19
Coming up in the next 3 weeks
- Lettuce: fall sowing Oct 19–Nov 16
- Lettuce: fall transplant Nov 2–23
- Spinach: fall sowing Nov 2–23
- Brussels sprouts: start seeds indoors Oct 26–Nov 9
- Kohlrabi: fall sowing Oct 19–Nov 2
- Bok choy / Asian greens: fall sowing Nov 2–16
- Arugula: fall sowing Nov 2–30
- Mustard greens: fall sowing Nov 2–16
- Swiss chard: fall sowing Oct 19–Nov 2
- Beet: fall sowing Oct 19–Nov 2
- Turnip: fall sowing Oct 19–Nov 2
- Onion (bulbing): start seeds indoors Oct 26–Nov 9
Prune now
No frost-timed pruning windows are open this week.
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 19 (prior Dec) |
| 50% (the "average" last frost) | Jan 18 |
| 10% (cautious: only 1 year in 10 freezes later) | Mar 1 |
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) | Dec 1 |
| 50% (the "average" first frost) | Dec 28 |
| 90% (late: most years have frozen by now) | Feb 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 18 | Dec 11 |
| 32°F (freeze) | Jan 18 | Dec 28 |
| 28°F (hard freeze) | Jan 9 | Jan 7 (next year) |
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 85173
Dates count from your average last spring frost (Jan 18) and first fall frost (Dec 28). 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 | Nov 23–Dec 7 | Jan 25–Feb 8 (transplant) | Aug 31–Sep 28 (transplant) |
| Pepper (sweet and hot) | Nov 9–23 | Feb 1–15 (transplant) | Sep 7–28 (transplant) |
| Eggplant | Nov 9–23 | Feb 1–15 (transplant) | Sep 7–28 (transplant) |
| Tomatillo | Nov 23–Dec 7 | Jan 25–Feb 8 (transplant) | – |
| Lettuce | Nov 23–Dec 7 | Dec 28–Jan 18 (transplant) Dec 21–Feb 1 (sow outdoors) | Nov 2–23 (transplant) Oct 19–Nov 16 (sowing) |
| Spinach | – | Dec 7–28 (sow outdoors) | Nov 2–23 (sowing) |
| Kale | Nov 23–Dec 7 | Dec 21–Jan 4 (transplant) Dec 21–Jan 4 (sow outdoors) | Oct 5–Nov 2 (transplant) Sep 21–Oct 19 (sowing) |
| Collards | Nov 23–Dec 7 | Dec 21–Jan 18 (transplant) Dec 21–Jan 18 (sow outdoors) | Oct 5–Nov 2 (transplant) Sep 21–Oct 19 (sowing) |
| Broccoli | Nov 9–23 | Dec 21–Jan 4 (transplant) | Sep 21–Oct 19 (transplant) |
| Cabbage | Nov 9–23 | Dec 21–Jan 4 (transplant) | Sep 21–Oct 19 (transplant) |
| Cauliflower | Nov 9–23 | Jan 4–18 (transplant) | Sep 21–Oct 19 (transplant) |
| Brussels sprouts | Oct 26–Nov 9 | Dec 21–Jan 4 (transplant) | Sep 7–28 (transplant) |
| Kohlrabi | Nov 23–Dec 7 | Dec 21–Jan 4 (transplant) Dec 21–Jan 4 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Bok choy / Asian greens | – | Dec 21–Jan 4 (sow outdoors) | Nov 2–16 (sowing) |
| Arugula | – | Dec 21–Jan 18 (sow outdoors) | Nov 2–30 (sowing) |
| Mustard greens | – | Dec 21–Jan 11 (sow outdoors) | Nov 2–16 (sowing) |
| Swiss chard | Dec 7–21 | Jan 4–25 (transplant) Jan 4–Feb 1 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Beet | – | Dec 21–Jan 18 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Carrot | – | Dec 28–Jan 25 (sow outdoors) | Oct 5–19 (sowing) |
| Radish | – | Dec 14–Jan 25 (sow outdoors) | Nov 16–30 (sowing) |
| Turnip | – | Dec 21–Jan 11 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Parsnip | – | Dec 28–Jan 18 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Nov 23–Dec 21 (sow outdoors) | Oct 5–19 (sowing) |
| Onion (bulbing) | Oct 26–Nov 9 | Dec 7–21 (transplant) | – |
| Green onion / scallion | – | Dec 7–Jan 4 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Leek | Oct 26–Nov 9 | Dec 21–Jan 4 (transplant) | – |
| Garlic | – | – | Nov 16–Dec 14 (sowing) |
| Shallot | – | Dec 7–21 (transplant) | Nov 16–Dec 14 (sowing) |
| Potato | – | Dec 21–Jan 4 (transplant) | Sep 7–21 (transplant) |
| Sweet potato | – | Feb 8–22 (transplant) | – |
| Sweet corn | – | Jan 25–Feb 8 (sow outdoors) | – |
| Bean, bush (snap) | – | Jan 25–Feb 8 (sow outdoors) | Oct 5–19 (sowing) |
| Bean, pole | – | Jan 25–Feb 8 (sow outdoors) | – |
| Lima bean | – | Feb 1–15 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Feb 8–Mar 1 (sow outdoors) | – |
| Cucumber | Dec 21–28 | Jan 25–Feb 8 (transplant) Jan 25–Feb 8 (sow outdoors) | Oct 5–19 (sowing) |
| Summer squash / zucchini | Dec 21–28 | Jan 25–Feb 8 (transplant) Jan 25–Feb 8 (sow outdoors) | Oct 5–19 (sowing) |
| Winter squash | Dec 21–28 | Jan 25–Feb 8 (transplant) Jan 25–Feb 8 (sow outdoors) | – |
| Pumpkin | – | Jan 25–Feb 8 (sow outdoors) | – |
| Watermelon | Dec 21–28 | Feb 1–15 (transplant) Feb 1–15 (sow outdoors) | – |
| Cantaloupe / muskmelon | Dec 21–28 | Feb 1–15 (transplant) Feb 1–15 (sow outdoors) | – |
| Okra | Dec 7–21 | Feb 1–15 (transplant) Feb 1–15 (sow outdoors) | – |
| Celery | Oct 26–Nov 9 | Jan 25–Feb 1 (transplant) | – |
| Basil | Dec 7–21 | Jan 25–Feb 8 (transplant) Jan 25–Feb 8 (sow outdoors) | – |
| Cilantro | – | Jan 4–Feb 1 (sow outdoors) | Nov 2–16 (sowing) |
| Parsley | Nov 9–23 | Jan 4–18 (transplant) Dec 28–Jan 18 (sow outdoors) | – |
| Dill | – | Jan 18–Feb 1 (sow outdoors) | Nov 2–16 (sowing) |
| Sunflower | – | Jan 18–Feb 1 (sow outdoors) | – |
| Asparagus (crowns) | – | Dec 21–Jan 4 (transplant) | – |
| Rhubarb (crowns) | – | Dec 21–Jan 4 (transplant) | – |
| Strawberry (plants) | – | Dec 21–Jan 4 (transplant) | Oct 19–Nov 16 (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: Superior, AZ (NOAA GHCN-Daily ID USC00028348), elevation 2,860 ft, 3.2 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Miami, AZ | 18 mi | Feb 24 | Dec 1 |
| Florence, AZ | 22 mi | Jan 30 | Dec 12 |
| Globe #3, AZ | 22 mi | Mar 11 | Nov 21 |
The average last-frost dates of these stations span 55 days, a rough guide to local variation. See data sources & methods.
Frost questions for 85173
When is the last frost in 85173?
The average (50% chance) last spring freeze of 32°F for ZIP 85173 is January 18. For a more cautious planting date, use March 1, when only 1 year in 10 still sees a later freeze.
When is the first frost in 85173?
The average first fall freeze is December 28. In 1 year in 10 it comes by December 1.
What hardiness zone is 85173?
ZIP 85173 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 85173 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
85137 Kearny 85539 Top-of-the-World 85118 Gold Canyon 85532 Claypool 85140 San Tan Valley 85545 Roosevelt Estates 85119 Apache Junction 85143 San Tan Valley
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 85191 85192 85193 85194 85618 All Pinal County frost dates · Arizona frost dates
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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.