When is the last frost in Byron, CA?

For ZIP code 94514, the average last spring frost (32°F) is January 19, based on NOAA 1991-2020 climate normals for the Tracy Pumping Plt, CA weather station. There is a 1-in-10 chance of a frost after February 17.

When is the first frost in Byron, CA?

The average first fall frost (32°F) is December 10. There is a 1-in-10 chance of frost by November 26, so tender plants are at risk from that point on.

How long is the growing season in 94514?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 330 days long.

Are these frost dates a forecast?

No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.

Frost dates for 94514Byron, CA

The average last spring frost in Byron is January 19 and the average first fall frost is December 10, giving a typical growing season of about 330 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 19
Average first fall frost: Dec 10
Growing season: 330 days

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
Temperature	Last spring: 90% / 50% / 10% chance	First fall: 10% / 50% / 90% chance	Growing season (50%)	Years with at least one
Light frost (36°F)	Jan 22 · Feb 21 · Mar 24	Nov 13 · Nov 29 · Dec 13	283 days	100%
Frost / freeze (32°F)	Dec 25 · Jan 19 · Feb 17	Nov 26 · Dec 10 · Jan 7	330 days	94%
Hard freeze (28°F)	Dec 12 · Jan 1 · Jan 22	Dec 4 · Dec 22 · Jan 10	361 days	58%

Where these dates come from

ZIP code 94514 is matched to the NOAA station Tracy Pumping Plt, CA, 4.8 km away, at 61 ft elevation (9 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Tracy Pumping Plt, CA (used)	61 ft	Jan 19	Dec 10
Antioch Pumping Plt #3, CA	60 ft	Jan 12	Dec 19
Livermore, CA	393 ft	Feb 15	Dec 2
Livermore Muni Ap, CA	393 ft	Feb 27	Dec 1

Frost dates near Byron

Discovery Bay, CA 94505 · last Jan 19, first Dec 10
Tracy, CA 95391 · last Jan 19, first Dec 10
Brentwood, CA 94513 · last Jan 12, first Dec 19
Livermore, CA 94551 · last Feb 27, first Dec 1
Knightsen, CA 94548 · last Jan 12, first Dec 19
Oakley, CA 94561 · last Jan 12, first Dec 19
Stockton, CA 95208 · last Feb 5, first Dec 8
Antioch, CA 94531 · last Jan 12, first Dec 19

Frequently asked questions

When is the last frost in Byron, CA?: For ZIP code 94514, the average last spring frost (32°F) is January 19, based on NOAA 1991-2020 climate normals for the Tracy Pumping Plt, CA weather station. There is a 1-in-10 chance of a frost after February 17.
When is the first frost in Byron, CA?: The average first fall frost (32°F) is December 10. There is a 1-in-10 chance of frost by November 26, so tender plants are at risk from that point on.
How long is the growing season in 94514?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 330 days long.
Are these frost dates a forecast?: No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.