Fall in zone 9aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 85730 (Tucson, 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, Saguaro Np, AZ (1 miles away).
- Average last spring frostJan 2650% chance of a 32°F freeze after this date
- Average first fall frostDec 1650% chance of a 32°F freeze by this date
- Growing season (frost-free)326 daysmedian, 32°F threshold
- USDA hardiness zone9a20 to 25°F avg. coldest night
Get The Dial for 85730 (Tucson)
Frost and freeze alerts from the NWS forecast for 85730, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
- Freeze alerts
- Soil-temp heads-up
- 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.
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
72°F 55°F or warmer
24-hour average · latest 69°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Tucson 11 W (27 mi), Elgin 5 S (43 mi), Walnut Gulch #1 (50 mi).
4-inch depth
72°F 55°F or warmer
24-hour average · latest 72°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Tucson 11 W (27 mi), Elgin 5 S (43 mi), Walnut Gulch #1 (50 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 85730 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 72°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 Mar 13 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 7–Nov 4
- Kale: fall transplant Sep 23–Oct 21
- Collards: fall transplant Sep 23–Oct 21
- Kohlrabi: fall sowing Oct 7–21
- Swiss chard: fall sowing Oct 7–21
- Beet: fall sowing Oct 7–21
- Turnip: fall sowing Oct 7–21
- Green onion / scallion: fall sowing Oct 7–21
- Strawberry (plants): fall transplant Oct 7–Nov 4
Coming up in the next 3 weeks
- Lettuce: fall transplant Oct 21–Nov 11
- Spinach: fall sowing Oct 21–Nov 11
- Brussels sprouts: start seeds indoors Nov 3–17
- Bok choy / Asian greens: fall sowing Oct 21–Nov 4
- Arugula: fall sowing Oct 21–Nov 18
- Mustard greens: fall sowing Oct 21–Nov 4
- Radish: fall sowing Nov 4–18
- Onion (bulbing): start seeds indoors Nov 3–17
- Leek: start seeds indoors Nov 3–17
- Garlic: fall sowing Nov 4–Dec 2
- Shallot: fall sowing Nov 4–Dec 2
- Celery: start seeds indoors Nov 3–17
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 24 (prior Dec) |
| 50% (the "average" last frost) | Jan 26 |
| 10% (cautious: only 1 year in 10 freezes later) | Feb 25 |
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 26 |
| 50% (the "average" first frost) | Dec 16 |
| 90% (late: most years have frozen by now) | Jan 17 (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 22 | Dec 2 |
| 32°F (freeze) | Jan 26 | Dec 16 |
| 28°F (hard freeze) | Jan 7 | Dec 28 |
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 85730
Dates count from your average last spring frost (Jan 26) and first fall frost (Dec 16). 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 1–15 | Feb 2–16 (transplant) | Aug 19–Sep 16 (transplant) |
| Pepper (sweet and hot) | Nov 17–Dec 1 | Feb 9–23 (transplant) | Aug 26–Sep 16 (transplant) |
| Eggplant | Nov 17–Dec 1 | Feb 9–23 (transplant) | Aug 26–Sep 16 (transplant) |
| Tomatillo | Dec 1–15 | Feb 2–16 (transplant) | – |
| Lettuce | Dec 1–15 | Jan 5–26 (transplant) Dec 29–Feb 9 (sow outdoors) | Oct 21–Nov 11 (transplant) Oct 7–Nov 4 (sowing) |
| Spinach | – | Dec 15–Jan 5 (sow outdoors) | Oct 21–Nov 11 (sowing) |
| Kale | Dec 1–15 | Dec 29–Jan 12 (transplant) Dec 29–Jan 12 (sow outdoors) | Sep 23–Oct 21 (transplant) Sep 9–Oct 7 (sowing) |
| Collards | Dec 1–15 | Dec 29–Jan 26 (transplant) Dec 29–Jan 26 (sow outdoors) | Sep 23–Oct 21 (transplant) Sep 9–Oct 7 (sowing) |
| Broccoli | Nov 17–Dec 1 | Dec 29–Jan 12 (transplant) | Sep 9–Oct 7 (transplant) |
| Cabbage | Nov 17–Dec 1 | Dec 29–Jan 12 (transplant) | Sep 9–Oct 7 (transplant) |
| Cauliflower | Nov 17–Dec 1 | Jan 12–26 (transplant) | Sep 9–Oct 7 (transplant) |
| Brussels sprouts | Nov 3–17 | Dec 29–Jan 12 (transplant) | Aug 26–Sep 16 (transplant) |
| Kohlrabi | Dec 1–15 | Dec 29–Jan 12 (transplant) Dec 29–Jan 12 (sow outdoors) | Oct 7–21 (sowing) |
| Bok choy / Asian greens | – | Dec 29–Jan 12 (sow outdoors) | Oct 21–Nov 4 (sowing) |
| Arugula | – | Dec 29–Jan 26 (sow outdoors) | Oct 21–Nov 18 (sowing) |
| Mustard greens | – | Dec 29–Jan 19 (sow outdoors) | Oct 21–Nov 4 (sowing) |
| Swiss chard | Dec 15–29 | Jan 12–Feb 2 (transplant) Jan 12–Feb 9 (sow outdoors) | Oct 7–21 (sowing) |
| Beet | – | Dec 29–Jan 26 (sow outdoors) | Oct 7–21 (sowing) |
| Carrot | – | Jan 5–Feb 2 (sow outdoors) | Sep 23–Oct 7 (sowing) |
| Radish | – | Dec 22–Feb 2 (sow outdoors) | Nov 4–18 (sowing) |
| Turnip | – | Dec 29–Jan 19 (sow outdoors) | Oct 7–21 (sowing) |
| Parsnip | – | Jan 5–26 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Dec 1–29 (sow outdoors) | Sep 23–Oct 7 (sowing) |
| Onion (bulbing) | Nov 3–17 | Dec 15–29 (transplant) | – |
| Green onion / scallion | – | Dec 15–Jan 12 (sow outdoors) | Oct 7–21 (sowing) |
| Leek | Nov 3–17 | Dec 29–Jan 12 (transplant) | – |
| Garlic | – | – | Nov 4–Dec 2 (sowing) |
| Shallot | – | Dec 15–29 (transplant) | Nov 4–Dec 2 (sowing) |
| Potato | – | Dec 29–Jan 12 (transplant) | Aug 26–Sep 9 (transplant) |
| Sweet potato | – | Feb 16–Mar 2 (transplant) | – |
| Sweet corn | – | Feb 2–16 (sow outdoors) | – |
| Bean, bush (snap) | – | Feb 2–16 (sow outdoors) | Sep 23–Oct 7 (sowing) |
| Bean, pole | – | Feb 2–16 (sow outdoors) | – |
| Lima bean | – | Feb 9–23 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Feb 16–Mar 9 (sow outdoors) | – |
| Cucumber | Dec 29–Jan 5 | Feb 2–16 (transplant) Feb 2–16 (sow outdoors) | Sep 23–Oct 7 (sowing) |
| Summer squash / zucchini | Dec 29–Jan 5 | Feb 2–16 (transplant) Feb 2–16 (sow outdoors) | Sep 23–Oct 7 (sowing) |
| Winter squash | Dec 29–Jan 5 | Feb 2–16 (transplant) Feb 2–16 (sow outdoors) | – |
| Pumpkin | – | Feb 2–16 (sow outdoors) | – |
| Watermelon | Dec 29–Jan 5 | Feb 9–23 (transplant) Feb 9–23 (sow outdoors) | – |
| Cantaloupe / muskmelon | Dec 29–Jan 5 | Feb 9–23 (transplant) Feb 9–23 (sow outdoors) | – |
| Okra | Dec 15–29 | Feb 9–23 (transplant) Feb 9–23 (sow outdoors) | – |
| Celery | Nov 3–17 | Feb 2–9 (transplant) | – |
| Basil | Dec 15–29 | Feb 2–16 (transplant) Feb 2–16 (sow outdoors) | – |
| Cilantro | – | Jan 12–Feb 9 (sow outdoors) | Oct 21–Nov 4 (sowing) |
| Parsley | Nov 17–Dec 1 | Jan 12–26 (transplant) Jan 5–26 (sow outdoors) | – |
| Dill | – | Jan 26–Feb 9 (sow outdoors) | Oct 21–Nov 4 (sowing) |
| Sunflower | – | Jan 26–Feb 9 (sow outdoors) | – |
| Asparagus (crowns) | – | Dec 29–Jan 12 (transplant) | – |
| Rhubarb (crowns) | – | Dec 29–Jan 12 (transplant) | – |
| Strawberry (plants) | – | Dec 29–Jan 12 (transplant) | Oct 7–Nov 4 (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: Saguaro Np, AZ (NOAA GHCN-Daily ID USC00027398), elevation 3,080 ft, 1.2 miles from the ZIP's center point. NOAA completeness flag: E (estimated from nearby stations).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Mt Lemmon Willow Canyon, AZ | 14 mi | Apr 1 | Nov 19 |
| Tucson WFO, AZ | 14 mi | Jan 20 | Dec 17 |
| Tucson Intl AP, AZ | 14 mi | Feb 5 | Dec 9 |
The average last-frost dates of these stations span 74 days, a rough guide to local variation. See data sources & methods.
Frost questions for 85730
When is the last frost in 85730?
The average (50% chance) last spring freeze of 32°F for ZIP 85730 is January 26. For a more cautious planting date, use February 25, when only 1 year in 10 still sees a later freeze.
When is the first frost in 85730?
The average first fall freeze is December 16. In 1 year in 10 it comes by November 26.
What hardiness zone is 85730?
ZIP 85730 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 85730 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
85748 Tucson 85710 Tucson 85749 Tanque Verde 85747 Tucson 85715 Tucson 85708 Tucson 85711 Tucson 85707 Tucson
Other ZIP codes in Pima County
85321 85341 85601 85614 85619 85622 85629 85633 85634 85639 85641 85645 85653 85654 85701 85704 85705 85706 85707 85708 85709 85710 85711 85712 All Pima County frost dates · Arizona frost dates
Never miss a frost: get The Dial
Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
- Soil-temp heads-up
- 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.