USDA Hardiness Zone 10a
Frost Dates for 92028 — Fallbrook, California
NOAA 1991–2020 normals from Fallbrook 5 NE, CA (1,140 ft), 4 miles north.
Updated
Frost is not a yearly event in Fallbrook: a night at or below 32°F came in 17% of the winters of 1991–2020 at Fallbrook 5 NE, CA, and a 36°F night, cold enough for frost on exposed leaves, in 73%. There is no reliable "last frost date" here; most years have none.
- Winters with a freeze
- 17%
- Winters with 36°F
- 73%
- Coldest month low
- 46°F
- Hardiness zone
- 10a
32°F or below, 1991–2020
frost possible on leaves
average, December
30 to 35°F (-1.1 to 1.7°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 5%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
1 of 19 observed
NOAA normal
Frost risk by date in Fallbrook
At Fallbrook 5 NE, CA, 4 miles north of Fallbrook, 17% of the winters of 1991–2020 had at least one night at or below 32°F, 0% reached 28°F. Nights of 36°F, enough for frost on exposed leaves, are more common (73% of winters) and, when they come, fall between about January 1 and February 7. February is the month most likely to bring one: a 9% chance in a given year. 62 of the 283 other California stations behind this site's ZIP pages freeze in fewer than half of winters too.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F73% of yrs | Dec 21 | Jan 3 | Jan 14 | Jan 27 | Feb 7 | Feb 16 | Feb 22 | Feb 28 | Mar 6 |
| 32°F17% of yrs | too rare for a date | ||||||||
| 28°F0% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F73% of yrs | Dec 11 | Dec 17 | Dec 23 | Dec 28 | Jan 1 | Jan 9 | Jan 20 | Feb 4 | Feb 17 |
| 32°F17% of yrs | too rare for a date | ||||||||
| 28°F0% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Fallbrook 5 NE, CA, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 92028 →Compare Fallbrook with another place →
Weather by month in Fallbrook
August is the warmest month at Fallbrook 5 NE, CA, averaging 89°F by day and 62°F at night; February is the coldest at 67°F and 46°F. Every month stays under a 10% chance of a 32°F night; February is the likeliest at 9%.
Warmth for growing adds up to 5,564 growing degree days a year (base 50°F), more than at 81% of the 283 California stations. 37% of them (2,050) have built up by the end of June, and August adds the most, 792. Precipitation totals 15.3 inches a year, most in February (3.7") and least in June (0.1"); May to September bring 6% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 68 | 47 | 3.2 | 5% | <1 | 242 |
| Feb | 67 | 46 | 3.7 | 9% | 0 | 200 |
| Mar | 70 | 48 | 2.0 | 0% | 0 | 282 |
| Apr | 72 | 51 | 1.0 | 0% | 0 | 340 |
| May | 75 | 53 | 0.4 | 0% | 0 | 436 |
| Jun | 81 | 56 | 0.1 | 0% | 0 | 551 |
| Jul | 87 | 60 | 0.1 | 0% | 0 | 732 |
| Aug | 89 | 62 | 0.2 | 0% | 0 | 792 |
| Sep | 88 | 62 | 0.1 | 0% | 0 | 742 |
| Oct | 83 | 58 | 0.7 | 0% | 0 | 637 |
| Nov | 74 | 52 | 1.2 | 0% | 0 | 395 |
| Dec | 67 | 46 | 2.6 | 4% | <1 | 216 |
Monthly normals 1991–2020 at Fallbrook 5 NE, CA (1,140 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Vista, CA, 10 miles south of Fallbrook and 710 feet lower, has a 32°F night in 35% of winters against 17% here, and a coolest-month low 1°F colder (45°F).
When it snows in Fallbrook, California
Measurable snow is rare here: only 1 of 19 winters from 1991 to 2020 recorded 0.1 inch or more at Vista, CA, 10.1 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 92028 is 4 miles from Fallbrook 5 NE, CA, which stands at 1,140 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 92592 (Temecula). The 2023 USDA Plant Hardiness Zone Map lists ZIP 92028 in zone 10a, the band where the coldest night of the year averaged 30 to 35°F (-1.1 to 1.7°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across California →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.