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Will it freeze in Sierra Madre in the next 7 nights?
No overnight lows at or below 32°F are forecast in Sierra Madre during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 58°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM PST to Fri, Nov 6, 6:00 AM PST.
No nights at or below 36°F in the National Weather Service forecast for the next 7 nights.
- Tonight 58°F Above 36°F · Mostly Clear
- Fri, Nov 6 59°F Above 36°F · Mostly Clear
- Sat, Nov 7 60°F Above 36°F · Clear
- Sun, Nov 8 62°F Above 36°F · Mostly Clear
- Mon, Nov 9 61°F Above 36°F · Partly Cloudy
- Tue, Nov 10 60°F Above 36°F · Mostly Clear
- Wed, Nov 11 59°F Above 36°F · Slight Chance Light Rain
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Sierra Madre
The median first fall hard-freeze date (28°F) is December 4, from NOAA’s 1991–2020 Climate Normals at Mt Wilson Cbs. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Apr 21 · May 15 · Jun 4 | Oct 3 · Oct 30 · Nov 19 | 167 days |
| 32°F freeze | Mar 31 · Apr 28 · May 27 | Oct 18 · Nov 15 · Dec 9 | 199 days |
| 28°F hard freeze | Feb 28 · Apr 8 · May 10 | Nov 5 · Dec 4 · Dec 29 | 240 days |
Average high temperature by month
1991–2020 normals at Mt Wilson Cbs
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Sierra Madre, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Mt Wilson Cbs (station USC00046006, elevation 5,710 ft), 4.5 mi from Sierra Madre. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Sierra Madre
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Arcadia, CA | 2.5 mi | rare | rare |
| Monrovia, CA | 3.7 mi | Apr 28 | Nov 15 |
| Temple City, CA | 4.3 mi | rare | rare |
| San Marino, CA | 5.0 mi | rare | rare |
| Pasadena, CA | 5.0 mi | rare | rare |
| Duarte, CA | 5.6 mi | Apr 28 | Nov 15 |
| San Gabriel, CA | 5.6 mi | rare | rare |
| El Monte, CA | 6.8 mi | rare | rare |
| Rosemead, CA | 7.5 mi | rare | rare |
| South Pasadena, CA | 7.5 mi | rare | rare |
Frequently asked questions
When is the last frost in Sierra Madre?
On average, the last spring frost (32°F) in Sierra Madre is around April 28. In about 1 year in 10 it comes after May 27, and in 9 years in 10 it comes after March 31.
When is the first frost in Sierra Madre?
The first fall frost (32°F) usually arrives around November 15. There’s a 10% chance of a freeze by October 18 and a 90% chance by December 9.
Can it frost in Sierra Madre after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after May 15.
What growing zone is Sierra Madre?
Sierra Madre is in USDA Plant Hardiness Zone 10a (average annual extreme minimum temperature 30 to 35°F), based on the 2023 USDA map for ZIP code 91024. See growing zones in California.
More: all California frost dates · California growing zones · frost vs. freeze