Frost dates in Modesto, California
NOAA 1991–2020 normals for a 32 °F freeze. Low spots and the edge of town run colder than downtown.
Short answer
The average last spring frost in Modesto is January 31, and the average first fall frost is December 5, from NOAA's Modesto City Co Airport station, 3 miles from the middle of Modesto. 1 year in 10 the last frost comes after February 25, and the first one by November 20. That leaves about 308 frost-free days. Modesto is in USDA planting zone 9b.
Weather stations around Modesto
The first row is the date most people in Modesto go by. The others show how far the dates move across the area.
| Station | Last spring frost | First fall frost | Frost-free |
|---|---|---|---|
| Modesto City Co Airport 3 mi away, 73 ft | January 31 1 in 10 after February 25 | December 5 1 in 10 by November 20 | 308 days |
| Turlock #2 13 mi away, 103 ft | January 6 1 in 10 after January 31 | December 20 1 in 10 by December 3 | 348 days |
| Tracy Carbona 19 mi away, 135 ft | February 25 1 in 10 after April 6 | November 26 1 in 10 by November 8 | 274 days |
| Stockton Metro Airport 21 mi away, 26 ft | February 6 1 in 10 after February 28 | December 1 1 in 10 by November 15 | 298 days |
| Newman 25 mi away, 90 ft | February 26 1 in 10 after April 21 | November 29 1 in 10 by November 12 | 276 days |
Distances are from the middle of Modesto as the Census Bureau maps it. The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. The planting zone is the USDA 2023 zone for ZIP code 95351, at the middle of the city.
Your exact ZIP code
Modesto covers a lot of ground. For the station nearest your own street, and its planting zone, type your ZIP code.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
More frost dates
All of California, station by station.
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Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)
- US Census Bureau, 2025 city population estimates and place gazetteer