Frost dates for Skyline Ridge Preserve, California
Half of years have their last spring frost by March 21, but 1 year in 10 still frosts after April 28.
A frost date is really a percentile from 30 years of records at a nearby weather station: in about half of years a frost still comes after the median date. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
How often a frost still comes on or after each date.
- 1 year in 10
- April 28
- 1 year in 5
- April 15
- 3 years in 10
- April 7
- 2 years in 5
- March 30
- Half of years (the median)
- March 21
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- November 21
- 1 year in 5
- November 29
- 3 years in 10
- December 5
- 2 years in 5
- December 10
- Half of years (the median)
- December 15
- Growing season
- about 275 days
- Hardiness zone nearby
- 9b
- Summer days
- a usual high of about 26 °C79 °F
- Lettuce and spinach run to seed
- June to September, in hot, long days (how we know)
Summer and rain
A growing garden needs about 25 mm1 in of water a week, rain and watering together. Here is what a normal month brings.
- Nearly every drop is yours
- June to September: rain brings less than a quarter of the water a growing garden needs, about 25 mm1 in a week (how we know)
Month by month
- January
- high ~13 °C55 °F · low ~5 °C41 °F · rain ~197 mm7.8 in
- February
- high ~13 °C55 °F · low ~5 °C40 °F · rain ~202 mm8 in
- March
- high ~15 °C58 °F · low ~5 °C41 °F · rain ~160 mm6.3 in
- April
- high ~16 °C62 °F · low ~6 °C43 °F · rain ~86 mm3.4 in
- May
- high ~19 °C67 °F · low ~8 °C47 °F · rain ~33 mm1.3 in
- June
- high ~24 °C75 °F · low ~11 °C52 °F · rain ~11 mm0.4 in
- July
- high ~27 °C81 °F · low ~14 °C58 °F · rain ~1 mm0.04 in
- August
- high ~27 °C81 °F · low ~15 °C58 °F · rain ~2.8 mm0.1 in
- September
- high ~26 °C79 °F · low ~14 °C57 °F · rain ~4.6 mm0.2 in
- October
- high ~22 °C71 °F · low ~11 °C52 °F · rain ~44 mm1.7 in
- November
- high ~16 °C60 °F · low ~7 °C44 °F · rain ~117 mm4.6 in
- December
- high ~12 °C54 °F · low ~4 °C40 °F · rain ~214 mm8.4 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Skyline Ridge Preserve station (listed by NOAA as Skyline Ridge Preserve, USC00048273), at 37.31, -122.19. These are that station’s own records, unshifted. The further your garden is from it, the less exactly they describe your ground. The planner finds the nearest station to your garden and lowers its confidence with distance, so no number is presented as if it were measured in your garden.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a few hundred feet away does not. No table can know that about your garden. A few seasons of your own logged frosts can.
ZIP codes nearest this station
94020, 94022, 94060, 94304, 95014.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Oakland Metro International Airport, CA, last frost by January 7
- Mt Hamilton, CA, last frost by May 3
- Livermore, CA, last frost by February 15
- San Francisco Oceanside, CA, frost is rare
- Oakland Museum, CA, frost is rare
- Lodi, CA, last frost by February 9
Other stations in California.
- Sacramento 5 ESE, CA, last frost by January 12
- Woodland 1 WNW, CA, last frost by February 7
- Auburn, CA, last frost by February 25
- Fresno 5 NE, CA, last frost by January 30
- Shelter Cove Aviation, CA, frost is rare
- Oxnard, CA, frost is rare
- Woodland Hills Pierce College, CA, last frost by January 24
- Burbank Glendale Pasadena Airport, CA, frost is rare
When do I plant? · Where the dates come from
More ways Milpa can help
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