Fall in zone 10aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 91763 (Montclair, 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, Pomona/fairplex, CA (4 miles away).
Freezes are uncommon here
NOAA's normals for this station show a 32°F night in about 65% 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 850% 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)354 daysmedian, 32°F threshold
- USDA hardiness zone10a30 to 35°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
77°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 Fallbrook 5 NE (53 mi).
4-inch depth
78°F 55°F or warmer
24-hour average · latest 76°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Fallbrook 5 NE (53 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 91763 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 78°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: 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 Feb 23 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
- 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
- Brussels sprouts: start seeds indoors Oct 16–30
- Carrot: fall sowing Oct 5–19
- Pea (garden, snap, snow): fall sowing Oct 5–19
- Onion (bulbing): start seeds indoors Oct 16–30
- Leek: start seeds indoors Oct 16–30
- Bean, bush (snap): fall sowing Oct 5–19
- Cucumber: fall sowing Oct 5–19
- Summer squash / zucchini: fall sowing Oct 5–19
- Celery: start seeds indoors Oct 16–30
Coming up in the next 3 weeks
- Pepper (sweet and hot): start seeds indoors Oct 30–Nov 13
- Eggplant: start seeds indoors Oct 30–Nov 13
- Lettuce: fall sowing Oct 19–Nov 16
- Lettuce: fall transplant Nov 2–23
- Spinach: fall sowing Nov 2–23
- Broccoli: start seeds indoors Oct 30–Nov 13
- Cabbage: start seeds indoors Oct 30–Nov 13
- Cauliflower: start seeds indoors Oct 30–Nov 13
- 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
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 14 (prior Dec) |
| 50% (the "average" last frost) | Jan 8 |
| 10% (cautious: only 1 year in 10 freezes later) | Feb 18 |
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 5 |
| 50% (the "average" first frost) | Dec 28 |
| 90% (late: most years have frozen by now) | Feb 2 (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 8 | Dec 10 |
| 32°F (freeze) | Jan 8 | Dec 28 |
| 28°F (hard freeze) | n/a | n/a |
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 91763
Dates count from your average last spring frost (Jan 8) 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 13–27 | Jan 15–29 (transplant) | Aug 31–Sep 28 (transplant) |
| Pepper (sweet and hot) | Oct 30–Nov 13 | Jan 22–Feb 5 (transplant) | Sep 7–28 (transplant) |
| Eggplant | Oct 30–Nov 13 | Jan 22–Feb 5 (transplant) | Sep 7–28 (transplant) |
| Tomatillo | Nov 13–27 | Jan 15–29 (transplant) | – |
| Lettuce | Nov 13–27 | Dec 18–Jan 8 (transplant) Dec 11–Jan 22 (sow outdoors) | Nov 2–23 (transplant) Oct 19–Nov 16 (sowing) |
| Spinach | – | Nov 27–Dec 18 (sow outdoors) | Nov 2–23 (sowing) |
| Kale | Nov 13–27 | Dec 11–25 (transplant) Dec 11–25 (sow outdoors) | Oct 5–Nov 2 (transplant) Sep 21–Oct 19 (sowing) |
| Collards | Nov 13–27 | Dec 11–Jan 8 (transplant) Dec 11–Jan 8 (sow outdoors) | Oct 5–Nov 2 (transplant) Sep 21–Oct 19 (sowing) |
| Broccoli | Oct 30–Nov 13 | Dec 11–25 (transplant) | Sep 21–Oct 19 (transplant) |
| Cabbage | Oct 30–Nov 13 | Dec 11–25 (transplant) | Sep 21–Oct 19 (transplant) |
| Cauliflower | Oct 30–Nov 13 | Dec 25–Jan 8 (transplant) | Sep 21–Oct 19 (transplant) |
| Brussels sprouts | Oct 16–30 | Dec 11–25 (transplant) | Sep 7–28 (transplant) |
| Kohlrabi | Nov 13–27 | Dec 11–25 (transplant) Dec 11–25 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Bok choy / Asian greens | – | Dec 11–25 (sow outdoors) | Nov 2–16 (sowing) |
| Arugula | – | Dec 11–Jan 8 (sow outdoors) | Nov 2–30 (sowing) |
| Mustard greens | – | Dec 11–Jan 1 (sow outdoors) | Nov 2–16 (sowing) |
| Swiss chard | Nov 27–Dec 11 | Dec 25–Jan 15 (transplant) Dec 25–Jan 22 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Beet | – | Dec 11–Jan 8 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Carrot | – | Dec 18–Jan 15 (sow outdoors) | Oct 5–19 (sowing) |
| Radish | – | Dec 4–Jan 15 (sow outdoors) | Nov 16–30 (sowing) |
| Turnip | – | Dec 11–Jan 1 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Parsnip | – | Dec 18–Jan 8 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Nov 13–Dec 11 (sow outdoors) | Oct 5–19 (sowing) |
| Onion (bulbing) | Oct 16–30 | Nov 27–Dec 11 (transplant) | – |
| Green onion / scallion | – | Nov 27–Dec 25 (sow outdoors) | Oct 19–Nov 2 (sowing) |
| Leek | Oct 16–30 | Dec 11–25 (transplant) | – |
| Garlic | – | – | Nov 16–Dec 14 (sowing) |
| Shallot | – | Nov 27–Dec 11 (transplant) | Nov 16–Dec 14 (sowing) |
| Potato | – | Dec 11–25 (transplant) | Sep 7–21 (transplant) |
| Sweet potato | – | Jan 29–Feb 12 (transplant) | – |
| Sweet corn | – | Jan 15–29 (sow outdoors) | – |
| Bean, bush (snap) | – | Jan 15–29 (sow outdoors) | Oct 5–19 (sowing) |
| Bean, pole | – | Jan 15–29 (sow outdoors) | – |
| Lima bean | – | Jan 22–Feb 5 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jan 29–Feb 19 (sow outdoors) | – |
| Cucumber | Dec 11–18 | Jan 15–29 (transplant) Jan 15–29 (sow outdoors) | Oct 5–19 (sowing) |
| Summer squash / zucchini | Dec 11–18 | Jan 15–29 (transplant) Jan 15–29 (sow outdoors) | Oct 5–19 (sowing) |
| Winter squash | Dec 11–18 | Jan 15–29 (transplant) Jan 15–29 (sow outdoors) | – |
| Pumpkin | – | Jan 15–29 (sow outdoors) | – |
| Watermelon | Dec 11–18 | Jan 22–Feb 5 (transplant) Jan 22–Feb 5 (sow outdoors) | – |
| Cantaloupe / muskmelon | Dec 11–18 | Jan 22–Feb 5 (transplant) Jan 22–Feb 5 (sow outdoors) | – |
| Okra | Nov 27–Dec 11 | Jan 22–Feb 5 (transplant) Jan 22–Feb 5 (sow outdoors) | – |
| Celery | Oct 16–30 | Jan 15–22 (transplant) | – |
| Basil | Nov 27–Dec 11 | Jan 15–29 (transplant) Jan 15–29 (sow outdoors) | – |
| Cilantro | – | Dec 25–Jan 22 (sow outdoors) | Nov 2–16 (sowing) |
| Parsley | Oct 30–Nov 13 | Dec 25–Jan 8 (transplant) Dec 18–Jan 8 (sow outdoors) | – |
| Dill | – | Jan 8–22 (sow outdoors) | Nov 2–16 (sowing) |
| Sunflower | – | Jan 8–22 (sow outdoors) | – |
| Asparagus (crowns) | – | Dec 11–25 (transplant) | – |
| Rhubarb (crowns) | – | Dec 11–25 (transplant) | – |
| Strawberry (plants) | – | Dec 11–25 (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: Pomona/fairplex, CA (NOAA GHCN-Daily ID USC00047050), elevation 999 ft, 3.9 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Ontario Intl AP, CA | 6 mi | Jan 4 | Dec 30 |
| Chino AP, CA | 8 mi | Jan 17 | Dec 19 |
| Riverside Muni AP, CA | 17 mi | Jan 9 | Dec 30 |
The average last-frost dates of these stations span 13 days, a rough guide to local variation. See data sources & methods.
Frost questions for 91763
When is the last frost in 91763?
The average (50% chance) last spring freeze of 32°F for ZIP 91763 is January 8. For a more cautious planting date, use February 18, when only 1 year in 10 still sees a later freeze.
When is the first frost in 91763?
The average first fall freeze is December 28. In 1 year in 10 it comes by December 5.
What hardiness zone is 91763?
ZIP 91763 is in USDA zone 10a (30 to 35°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 91763 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
91762 Ontario 91767 Pomona 91786 Upland 91766 Pomona 91711 Claremont 91710 Chino 91764 Ontario 91768 Pomona
Other ZIP codes in San Bernardino County
91701 91708 91709 91710 91730 91737 91739 91761 91762 91764 91784 91786 92242 92252 92256 92267 92268 92277 92278 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.