Fall in zone 8bPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 85601 (Arivaca, 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, Sasabe, AZ (14 miles away).
- Average last spring frostMar 2150% chance of a 32°F freeze after this date
- Average first fall frostNov 2050% chance of a 32°F freeze by this date
- Growing season (frost-free)246 daysmedian, 32°F threshold
- USDA hardiness zone8b15 to 20°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
70°F 55°F or warmer
24-hour average · latest 68°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Tucson 11 W (46 mi), Elgin 5 S (48 mi).
4-inch depth
71°F 55°F or warmer
24-hour average · latest 71°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Tucson 11 W (46 mi), Elgin 5 S (48 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 85601 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 71°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
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 May 6 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 25–Oct 23
- Radish: fall sowing Oct 9–23
- Garlic: fall sowing Oct 9–Nov 6
- Shallot: fall sowing Oct 9–Nov 6
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 20: 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 23 |
| 50% (the "average" last frost) | Mar 21 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 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 1 |
| 50% (the "average" first frost) | Nov 20 |
| 90% (late: most years have frozen by now) | Dec 7 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 14 | Nov 8 |
| 32°F (freeze) | Mar 21 | Nov 20 |
| 28°F (hard freeze) | Feb 20 | Dec 3 |
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 85601
Dates count from your average last spring frost (Mar 21) and first fall frost (Nov 20). 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 24–Feb 7 | Mar 28–Apr 11 (transplant) | Jul 24–Aug 21 (transplant) |
| Pepper (sweet and hot) | Jan 10–24 | Apr 4–18 (transplant) | Jul 31–Aug 21 (transplant) |
| Eggplant | Jan 10–24 | Apr 4–18 (transplant) | Jul 31–Aug 21 (transplant) |
| Tomatillo | Jan 24–Feb 7 | Mar 28–Apr 11 (transplant) | – |
| Lettuce | Jan 24–Feb 7 | Feb 28–Mar 21 (transplant) Feb 21–Apr 4 (sow outdoors) | Sep 25–Oct 16 (transplant) Sep 11–Oct 9 (sowing) |
| Spinach | – | Feb 7–28 (sow outdoors) | Sep 25–Oct 16 (sowing) |
| Kale | Jan 24–Feb 7 | Feb 21–Mar 7 (transplant) Feb 21–Mar 7 (sow outdoors) | Aug 28–Sep 25 (transplant) Aug 14–Sep 11 (sowing) |
| Collards | Jan 24–Feb 7 | Feb 21–Mar 21 (transplant) Feb 21–Mar 21 (sow outdoors) | Aug 28–Sep 25 (transplant) Aug 14–Sep 11 (sowing) |
| Broccoli | Jan 10–24 | Feb 21–Mar 7 (transplant) | Aug 14–Sep 11 (transplant) |
| Cabbage | Jan 10–24 | Feb 21–Mar 7 (transplant) | Aug 14–Sep 11 (transplant) |
| Cauliflower | Jan 10–24 | Mar 7–21 (transplant) | Aug 14–Sep 11 (transplant) |
| Brussels sprouts | Dec 27–Jan 10 | Feb 21–Mar 7 (transplant) | Jul 31–Aug 21 (transplant) |
| Kohlrabi | Jan 24–Feb 7 | Feb 21–Mar 7 (transplant) Feb 21–Mar 7 (sow outdoors) | Sep 11–25 (sowing) |
| Bok choy / Asian greens | – | Feb 21–Mar 7 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Arugula | – | Feb 21–Mar 21 (sow outdoors) | Sep 25–Oct 23 (sowing) |
| Mustard greens | – | Feb 21–Mar 14 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Swiss chard | Feb 7–21 | Mar 7–28 (transplant) Mar 7–Apr 4 (sow outdoors) | Sep 11–25 (sowing) |
| Beet | – | Feb 21–Mar 21 (sow outdoors) | Sep 11–25 (sowing) |
| Carrot | – | Feb 28–Mar 28 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Radish | – | Feb 14–Mar 28 (sow outdoors) | Oct 9–23 (sowing) |
| Turnip | – | Feb 21–Mar 14 (sow outdoors) | Sep 11–25 (sowing) |
| Parsnip | – | Feb 28–Mar 21 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Jan 24–Feb 21 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Onion (bulbing) | Dec 27–Jan 10 | Feb 7–21 (transplant) | – |
| Green onion / scallion | – | Feb 7–Mar 7 (sow outdoors) | Sep 11–25 (sowing) |
| Leek | Dec 27–Jan 10 | Feb 21–Mar 7 (transplant) | – |
| Garlic | – | – | Oct 9–Nov 6 (sowing) |
| Shallot | – | Feb 7–21 (transplant) | Oct 9–Nov 6 (sowing) |
| Potato | – | Feb 21–Mar 7 (transplant) | Jul 31–Aug 14 (transplant) |
| Sweet potato | – | Apr 11–25 (transplant) | – |
| Sweet corn | – | Mar 28–Apr 11 (sow outdoors) | – |
| Bean, bush (snap) | – | Mar 28–Apr 11 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Bean, pole | – | Mar 28–Apr 11 (sow outdoors) | – |
| Lima bean | – | Apr 4–18 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Apr 11–May 2 (sow outdoors) | – |
| Cucumber | Feb 21–28 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Summer squash / zucchini | Feb 21–28 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Winter squash | Feb 21–28 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | – |
| Pumpkin | – | Mar 28–Apr 11 (sow outdoors) | – |
| Watermelon | Feb 21–28 | Apr 4–18 (transplant) Apr 4–18 (sow outdoors) | – |
| Cantaloupe / muskmelon | Feb 21–28 | Apr 4–18 (transplant) Apr 4–18 (sow outdoors) | – |
| Okra | Feb 7–21 | Apr 4–18 (transplant) Apr 4–18 (sow outdoors) | – |
| Celery | Dec 27–Jan 10 | Mar 28–Apr 4 (transplant) | – |
| Basil | Feb 7–21 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | – |
| Cilantro | – | Mar 7–Apr 4 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Parsley | Jan 10–24 | Mar 7–21 (transplant) Feb 28–Mar 21 (sow outdoors) | – |
| Dill | – | Mar 21–Apr 4 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Sunflower | – | Mar 21–Apr 4 (sow outdoors) | – |
| Asparagus (crowns) | – | Feb 21–Mar 7 (transplant) | – |
| Rhubarb (crowns) | – | Feb 21–Mar 7 (transplant) | – |
| Strawberry (plants) | – | Feb 21–Mar 7 (transplant) | Sep 11–Oct 9 (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: Sasabe, AZ (NOAA GHCN-Daily ID USC00027619), elevation 3,590 ft, 14.3 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Tumacacori Nm, AZ | 17 mi | Apr 5 | Nov 10 |
| Nogales 6 N, AZ | 23 mi | Apr 16 | Nov 2 |
| Anvil Rch, AZ | 28 mi | Mar 27 | Nov 9 |
The average last-frost dates of these stations span 26 days, a rough guide to local variation. See data sources & methods.
Frost questions for 85601
When is the last frost in 85601?
The average (50% chance) last spring freeze of 32°F for ZIP 85601 is March 21. For a more cautious planting date, use April 14, when only 1 year in 10 still sees a later freeze.
When is the first frost in 85601?
The average first fall freeze is November 20. In 1 year in 10 it comes by November 1.
What hardiness zone is 85601?
ZIP 85601 is in USDA zone 8b (15 to 20°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 85601 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
85633 85645 Elephant Head 85646 Tubac 85640 Tumacacori-Carmen 85736 Three Points 85648 Rio Rico 85622 Green Valley 85639 Topawa
Other ZIP codes in Pima County
85321 85341 85614 85619 85622 85629 85633 85634 85639 85641 85645 85653 85654 85701 85704 85705 85706 85707 85708 85709 85710 85711 85712 85713 All Pima 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.