Fall in zone 10aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 91016 (Monrovia, 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, Mt Wilson Cbs, CA (7 miles away).
- Average last spring frostApr 2850% chance of a 32°F freeze after this date
- Average first fall frostNov 1550% chance of a 32°F freeze by this date
- Growing season (frost-free)199 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
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 91016 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 February to March; fall 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 Jun 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).
- 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
- Arugula: fall sowing Sep 20–Oct 18
- Radish: fall sowing Oct 4–18
- Garlic: fall sowing Oct 4–Nov 1
- Shallot: fall sowing Oct 4–Nov 1
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 15: 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) | Mar 31 |
| 50% (the "average" last frost) | Apr 28 |
| 10% (cautious: only 1 year in 10 freezes later) | May 27 |
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) | Oct 18 |
| 50% (the "average" first frost) | Nov 15 |
| 90% (late: most years have frozen by now) | Dec 9 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 15 | Oct 30 |
| 32°F (freeze) | Apr 28 | Nov 15 |
| 28°F (hard freeze) | Apr 8 | Dec 4 |
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 91016
Dates count from your average last spring frost (Apr 28) and first fall frost (Nov 15). 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 | Mar 3–17 | May 5–19 (transplant) | – |
| Pepper (sweet and hot) | Feb 17–Mar 3 | May 12–26 (transplant) | – |
| Eggplant | Feb 17–Mar 3 | May 12–26 (transplant) | – |
| Tomatillo | Mar 3–17 | May 5–19 (transplant) | – |
| Lettuce | Mar 3–17 | Apr 7–28 (transplant) Mar 31–May 12 (sow outdoors) | Sep 20–Oct 11 (transplant) Sep 6–Oct 4 (sowing) |
| Spinach | – | Mar 17–Apr 7 (sow outdoors) | Sep 20–Oct 11 (sowing) |
| Kale | Mar 3–17 | Mar 31–Apr 14 (transplant) Mar 31–Apr 14 (sow outdoors) | Aug 23–Sep 20 (transplant) Aug 9–Sep 6 (sowing) |
| Collards | Mar 3–17 | Mar 31–Apr 28 (transplant) Mar 31–Apr 28 (sow outdoors) | Aug 23–Sep 20 (transplant) Aug 9–Sep 6 (sowing) |
| Broccoli | Feb 17–Mar 3 | Mar 31–Apr 14 (transplant) | Aug 9–Sep 6 (transplant) |
| Cabbage | Feb 17–Mar 3 | Mar 31–Apr 14 (transplant) | Aug 9–Sep 6 (transplant) |
| Cauliflower | Feb 17–Mar 3 | Apr 14–28 (transplant) | Aug 9–Sep 6 (transplant) |
| Brussels sprouts | Feb 3–17 | Mar 31–Apr 14 (transplant) | Jul 26–Aug 16 (transplant) |
| Kohlrabi | Mar 3–17 | Mar 31–Apr 14 (transplant) Mar 31–Apr 14 (sow outdoors) | Sep 6–20 (sowing) |
| Bok choy / Asian greens | – | Mar 31–Apr 14 (sow outdoors) | Sep 20–Oct 4 (sowing) |
| Arugula | – | Mar 31–Apr 28 (sow outdoors) | Sep 20–Oct 18 (sowing) |
| Mustard greens | – | Mar 31–Apr 21 (sow outdoors) | Sep 20–Oct 4 (sowing) |
| Swiss chard | Mar 17–31 | Apr 14–May 5 (transplant) Apr 14–May 12 (sow outdoors) | Sep 6–20 (sowing) |
| Beet | – | Mar 31–Apr 28 (sow outdoors) | Sep 6–20 (sowing) |
| Carrot | – | Apr 7–May 5 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Radish | – | Mar 24–May 5 (sow outdoors) | Oct 4–18 (sowing) |
| Turnip | – | Mar 31–Apr 21 (sow outdoors) | Sep 6–20 (sowing) |
| Parsnip | – | Apr 7–28 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 3–31 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Onion (bulbing) | Feb 3–17 | Mar 17–31 (transplant) | – |
| Green onion / scallion | – | Mar 17–Apr 14 (sow outdoors) | Sep 6–20 (sowing) |
| Leek | Feb 3–17 | Mar 31–Apr 14 (transplant) | – |
| Garlic | – | – | Oct 4–Nov 1 (sowing) |
| Shallot | – | Mar 17–31 (transplant) | Oct 4–Nov 1 (sowing) |
| Potato | – | Mar 31–Apr 14 (transplant) | Jul 26–Aug 9 (transplant) |
| Sweet potato | – | May 19–Jun 2 (transplant) | – |
| Sweet corn | – | May 5–19 (sow outdoors) | – |
| Bean, bush (snap) | – | May 5–19 (sow outdoors) | – |
| Bean, pole | – | May 5–19 (sow outdoors) | – |
| Lima bean | – | May 12–26 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 19–Jun 9 (sow outdoors) | – |
| Cucumber | Mar 31–Apr 7 | May 5–19 (transplant) May 5–19 (sow outdoors) | – |
| Summer squash / zucchini | Mar 31–Apr 7 | May 5–19 (transplant) May 5–19 (sow outdoors) | – |
| Winter squash | Mar 31–Apr 7 | May 5–19 (transplant) May 5–19 (sow outdoors) | – |
| Pumpkin | – | May 5–19 (sow outdoors) | – |
| Watermelon | Mar 31–Apr 7 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 31–Apr 7 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Okra | Mar 17–31 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Celery | Feb 3–17 | May 5–12 (transplant) | – |
| Basil | Mar 17–31 | May 5–19 (transplant) May 5–19 (sow outdoors) | – |
| Cilantro | – | Apr 14–May 12 (sow outdoors) | Sep 20–Oct 4 (sowing) |
| Parsley | Feb 17–Mar 3 | Apr 14–28 (transplant) Apr 7–28 (sow outdoors) | – |
| Dill | – | Apr 28–May 12 (sow outdoors) | Sep 20–Oct 4 (sowing) |
| Sunflower | – | Apr 28–May 12 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 31–Apr 14 (transplant) | – |
| Rhubarb (crowns) | – | Mar 31–Apr 14 (transplant) | – |
| Strawberry (plants) | – | Mar 31–Apr 14 (transplant) | Sep 6–Oct 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: Mt Wilson Cbs, CA (NOAA GHCN-Daily ID USC00046006), elevation 5,710 ft, 6.7 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| San Gabriel Fire Dept, CA | 7 mi | Jan 4 | Jan 2 (next year) |
| Pasadena, CA | 8 mi | Jan 8 | Jan 7 (next year) |
| Pomona/fairplex, CA | 14 mi | Jan 8 | Dec 28 |
The average last-frost dates of these stations span 117 days, a rough guide to local variation. See data sources & methods.
Frost questions for 91016
When is the last frost in 91016?
The average (50% chance) last spring freeze of 32°F for ZIP 91016 is April 28. For a more cautious planting date, use May 27, when only 1 year in 10 still sees a later freeze.
When is the first frost in 91016?
The average first fall freeze is November 15. In 1 year in 10 it comes by October 18.
What hardiness zone is 91016?
ZIP 91016 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 91016 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.
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Other ZIP codes in Los Angeles County
90001 90002 90003 90004 90005 90006 90007 90008 90010 90011 90012 90013 90014 90015 90016 90017 90018 90019 90020 90021 90022 90023 90024 90025 All Los Angeles County frost dates · California 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.