USDA Hardiness Zone 10b
Frost Dates for 94124 — San Francisco, California
NOAA 1991–2020 normals from San Francisco Dwtn, CA (150 ft), 3 miles northwest.
Updated
No night at or below 32°F was recorded at San Francisco Dwtn, CA in 1991–2020, so San Francisco has no frost dates to plan around; the coolest month, January, averages a low of 47°F.
- Winters with a freeze
- 0%
- Winters with 36°F
- 9%
- Coldest month low
- 47°F
- Hardiness zone
- 10b
32°F or below, 1991–2020
frost possible on leaves
average, January
35 to 40°F (1.7 to 4.4°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 20 observed
NOAA normal
Frost risk by date in San Francisco
San Francisco Dwtn, CA, 3 miles northwest of San Francisco, did not record a night at or below 32°F in 1991–2020; a 36°F night came in 9% of winters. 10 of the 283 other California stations behind this site's ZIP pages recorded no 32°F night either.
Freeze probabilities 1991–2020 at San Francisco Dwtn, 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 94124 →Compare San Francisco with another place →
Weather by month in San Francisco
September is the warmest month at San Francisco Dwtn, CA, averaging 70°F by day and 56°F at night; January is the coldest at 58°F and 47°F. Not one month recorded a 32°F night; the lowest monthly average low is 47°F.
Warmth for growing adds up to 2,872 growing degree days a year (base 50°F), fewer than at 86% of the 283 California stations. 39% of them (1,114) have built up by the end of June, and September adds the most, 387. Precipitation totals 23.0 inches a year, most in December (4.8") and least in July (0.0"); May to September bring 5% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 58 | 47 | 4.4 | 0% | 0 | 89 |
| Feb | 60 | 48 | 4.4 | 0% | 0 | 125 |
| Mar | 62 | 49 | 3.2 | 0% | 0 | 176 |
| Apr | 63 | 50 | 1.6 | 0% | 0 | 192 |
| May | 64 | 51 | 0.7 | 0% | 0 | 240 |
| Jun | 67 | 53 | 0.2 | 0% | 0 | 293 |
| Jul | 66 | 54 | 0.0 | 0% | 0 | 321 |
| Aug | 68 | 56 | 0.1 | 0% | 0 | 363 |
| Sep | 70 | 56 | 0.1 | 0% | 0 | 387 |
| Oct | 70 | 54 | 0.9 | 0% | 0 | 375 |
| Nov | 64 | 51 | 2.6 | 0% | 0 | 218 |
| Dec | 58 | 47 | 4.8 | 0% | 0 | 94 |
Monthly normals 1991–2020 at San Francisco Dwtn, CA (150 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, San Francisco Oceanside, CA, 6 miles west of San Francisco, has a 32°F night in 22% of winters against 0% here, and a coolest-month low 1°F colder (46°F).
When it snows in San Francisco, California
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at San Francisco Oceanside, CA, 6.1 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 94124 is 3 miles from San Francisco Dwtn, CA, which stands at 150 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 20 other ZIP codes share the station; its figures are presented in full for 94110 (San Francisco). The 2023 USDA Plant Hardiness Zone Map lists ZIP 94124 in zone 10b, the band where the coldest night of the year averaged 35 to 40°F (1.7 to 4.4°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.