Fall in zone 9bPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 92278 (Twentynine Palms, CA)
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, Twentynine Palms, CA (8 miles away).
- Average last spring frostJan 2450% chance of a 32°F freeze after this date
- Average first fall frostDec 1050% chance of a 32°F freeze by this date
- Growing season (frost-free)321 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
73°F 55°F or warmer
24-hour average · latest 68°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Desert Center (53 mi), Essex (59 mi).
4-inch depth
74°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 Desert Center (53 mi), Essex (59 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 92278 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 74°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: California coastal and valleys. Timing only; always follow the product label.
- Bermudagrass (warm-season): Spring: Several weeks after the lawn is fully green (April–May) (about Mar 11 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).
- Tall fescue (cool-season): Early fall: September (main feeding); Late fall: November, while still green; Late winter: Optional light feeding February–March. Avoid: Feeding after mid-spring and through summer in the transition zone (stress and brown patch).
Plant now
- Lettuce: fall sowing Oct 1–29
- Lettuce: fall transplant Oct 15–Nov 5
- Spinach: fall sowing Oct 15–Nov 5
- Bok choy / Asian greens: fall sowing Oct 15–29
- Arugula: fall sowing Oct 15–Nov 12
- Mustard greens: fall sowing Oct 15–29
- Cilantro: fall sowing Oct 15–29
- Dill: fall sowing Oct 15–29
- Strawberry (plants): fall transplant Oct 1–29
Coming up in the next 3 weeks
- Brussels sprouts: start seeds indoors Nov 1–15
- Radish: fall sowing Oct 29–Nov 12
- Onion (bulbing): start seeds indoors Nov 1–15
- Leek: start seeds indoors Nov 1–15
- Garlic: fall sowing Oct 29–Nov 26
- Shallot: fall sowing Oct 29–Nov 26
- Celery: start seeds indoors Nov 1–15
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Dec 10: 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 22 (prior Dec) |
| 50% (the "average" last frost) | Jan 24 |
| 10% (cautious: only 1 year in 10 freezes later) | Feb 22 |
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 24 |
| 50% (the "average" first frost) | Dec 10 |
| 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 19 | Nov 27 |
| 32°F (freeze) | Jan 24 | Dec 10 |
| 28°F (hard freeze) | Jan 3 | Dec 23 |
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 92278
Dates count from your average last spring frost (Jan 24) and first fall frost (Dec 10). 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 29–Dec 13 | Jan 31–Feb 14 (transplant) | Aug 13–Sep 10 (transplant) |
| Pepper (sweet and hot) | Nov 15–29 | Feb 7–21 (transplant) | Aug 20–Sep 10 (transplant) |
| Eggplant | Nov 15–29 | Feb 7–21 (transplant) | Aug 20–Sep 10 (transplant) |
| Tomatillo | Nov 29–Dec 13 | Jan 31–Feb 14 (transplant) | – |
| Lettuce | Nov 29–Dec 13 | Jan 3–24 (transplant) Dec 27–Feb 7 (sow outdoors) | Oct 15–Nov 5 (transplant) Oct 1–29 (sowing) |
| Spinach | – | Dec 13–Jan 3 (sow outdoors) | Oct 15–Nov 5 (sowing) |
| Kale | Nov 29–Dec 13 | Dec 27–Jan 10 (transplant) Dec 27–Jan 10 (sow outdoors) | Sep 17–Oct 15 (transplant) Sep 3–Oct 1 (sowing) |
| Collards | Nov 29–Dec 13 | Dec 27–Jan 24 (transplant) Dec 27–Jan 24 (sow outdoors) | Sep 17–Oct 15 (transplant) Sep 3–Oct 1 (sowing) |
| Broccoli | Nov 15–29 | Dec 27–Jan 10 (transplant) | Sep 3–Oct 1 (transplant) |
| Cabbage | Nov 15–29 | Dec 27–Jan 10 (transplant) | Sep 3–Oct 1 (transplant) |
| Cauliflower | Nov 15–29 | Jan 10–24 (transplant) | Sep 3–Oct 1 (transplant) |
| Brussels sprouts | Nov 1–15 | Dec 27–Jan 10 (transplant) | Aug 20–Sep 10 (transplant) |
| Kohlrabi | Nov 29–Dec 13 | Dec 27–Jan 10 (transplant) Dec 27–Jan 10 (sow outdoors) | Oct 1–15 (sowing) |
| Bok choy / Asian greens | – | Dec 27–Jan 10 (sow outdoors) | Oct 15–29 (sowing) |
| Arugula | – | Dec 27–Jan 24 (sow outdoors) | Oct 15–Nov 12 (sowing) |
| Mustard greens | – | Dec 27–Jan 17 (sow outdoors) | Oct 15–29 (sowing) |
| Swiss chard | Dec 13–27 | Jan 10–31 (transplant) Jan 10–Feb 7 (sow outdoors) | Oct 1–15 (sowing) |
| Beet | – | Dec 27–Jan 24 (sow outdoors) | Oct 1–15 (sowing) |
| Carrot | – | Jan 3–31 (sow outdoors) | Sep 17–Oct 1 (sowing) |
| Radish | – | Dec 20–Jan 31 (sow outdoors) | Oct 29–Nov 12 (sowing) |
| Turnip | – | Dec 27–Jan 17 (sow outdoors) | Oct 1–15 (sowing) |
| Parsnip | – | Jan 3–24 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Nov 29–Dec 27 (sow outdoors) | Sep 17–Oct 1 (sowing) |
| Onion (bulbing) | Nov 1–15 | Dec 13–27 (transplant) | – |
| Green onion / scallion | – | Dec 13–Jan 10 (sow outdoors) | Oct 1–15 (sowing) |
| Leek | Nov 1–15 | Dec 27–Jan 10 (transplant) | – |
| Garlic | – | – | Oct 29–Nov 26 (sowing) |
| Shallot | – | Dec 13–27 (transplant) | Oct 29–Nov 26 (sowing) |
| Potato | – | Dec 27–Jan 10 (transplant) | Aug 20–Sep 3 (transplant) |
| Sweet potato | – | Feb 14–28 (transplant) | – |
| Sweet corn | – | Jan 31–Feb 14 (sow outdoors) | – |
| Bean, bush (snap) | – | Jan 31–Feb 14 (sow outdoors) | Sep 17–Oct 1 (sowing) |
| Bean, pole | – | Jan 31–Feb 14 (sow outdoors) | – |
| Lima bean | – | Feb 7–21 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Feb 14–Mar 7 (sow outdoors) | – |
| Cucumber | Dec 27–Jan 3 | Jan 31–Feb 14 (transplant) Jan 31–Feb 14 (sow outdoors) | Sep 17–Oct 1 (sowing) |
| Summer squash / zucchini | Dec 27–Jan 3 | Jan 31–Feb 14 (transplant) Jan 31–Feb 14 (sow outdoors) | Sep 17–Oct 1 (sowing) |
| Winter squash | Dec 27–Jan 3 | Jan 31–Feb 14 (transplant) Jan 31–Feb 14 (sow outdoors) | – |
| Pumpkin | – | Jan 31–Feb 14 (sow outdoors) | – |
| Watermelon | Dec 27–Jan 3 | Feb 7–21 (transplant) Feb 7–21 (sow outdoors) | – |
| Cantaloupe / muskmelon | Dec 27–Jan 3 | Feb 7–21 (transplant) Feb 7–21 (sow outdoors) | – |
| Okra | Dec 13–27 | Feb 7–21 (transplant) Feb 7–21 (sow outdoors) | – |
| Celery | Nov 1–15 | Jan 31–Feb 7 (transplant) | – |
| Basil | Dec 13–27 | Jan 31–Feb 14 (transplant) Jan 31–Feb 14 (sow outdoors) | – |
| Cilantro | – | Jan 10–Feb 7 (sow outdoors) | Oct 15–29 (sowing) |
| Parsley | Nov 15–29 | Jan 10–24 (transplant) Jan 3–24 (sow outdoors) | – |
| Dill | – | Jan 24–Feb 7 (sow outdoors) | Oct 15–29 (sowing) |
| Sunflower | – | Jan 24–Feb 7 (sow outdoors) | – |
| Asparagus (crowns) | – | Dec 27–Jan 10 (transplant) | – |
| Rhubarb (crowns) | – | Dec 27–Jan 10 (transplant) | – |
| Strawberry (plants) | – | Dec 27–Jan 10 (transplant) | Oct 1–29 (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: Twentynine Palms, CA (NOAA GHCN-Daily ID USC00049099), elevation 1,975 ft, 7.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Joshua Tree, CA | 14 mi | Feb 28 | Dec 1 |
| Yucca Mesa, CA | 20 mi | Feb 16 | Dec 10 |
| Yucca Valley, CA | 20 mi | Mar 14 | Nov 28 |
The average last-frost dates of these stations span 52 days, a rough guide to local variation. See data sources & methods.
Frost questions for 92278
When is the last frost in 92278?
The average (50% chance) last spring freeze of 32°F for ZIP 92278 is January 24. For a more cautious planting date, use February 22, when only 1 year in 10 still sees a later freeze.
When is the first frost in 92278?
The average first fall freeze is December 10. In 1 year in 10 it comes by November 24.
What hardiness zone is 92278?
ZIP 92278 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 92278 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
92252 Joshua Tree 92284 Yucca Valley 92277 Twentynine Palms 92285 Homestead Valley 92268 92241 Sky Valley 92304 92240 Desert Hot Springs
Other ZIP codes in San Bernardino County
91701 91708 91709 91710 91730 91737 91739 91761 91762 91763 91764 91784 91786 92242 92252 92256 92267 92268 92277 92280 92284 92285 92301 92304 All San Bernardino County frost dates · California 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.