Frost Dates for San Francisco, California, United States of America

Coordinates: 37.775, -122.418

Growing Season

The last spring air frost in San Francisco, California, United States of America typically occurs around Feb 10, and the first autumn air frost around Dec 10. This gives a frost-free growing season of approximately 304 days.

USDA Hardiness Zone

This location falls in USDA Hardiness Zone 10a, where the average annual extreme minimum temperature is -1.1 to 1.7°C (30 to 35°F). This zone rating helps gardeners determine which perennial plants are likely to survive winter.

Temperature Overview

The coldest month is January, with an average low of 8°C (46°F). The warmest month is September, with an average high of 23°C (73°F).

Frost Risk Breakdown

Frost dates at three temperature thresholds: Air frost (0°C / 32°F): Feb 10 (last spring) to Dec 10 (first autumn).

We predict your growing zone to be approximately ...

USDA Growing Zone
USDA Growing Zone - 10a

... and the frost data for your area is ...

Current Risk Level: Unlikely (Safest)

for today based on past data only.

We predict a frost free growing season at your location from Feb 10 to Dec 10, which provides approximately 302 frost free days.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  • Air Frost possible
  • Safest (unlikely)
First and last frost dates by frost type
FirstLast
Air FrostDec 10Feb 10
Light Ground FrostUnlikelyUnlikely
Hard Ground FrostUnlikelyUnlikely

Frost Dates for San Francisco, California, United States of America | FrostDates.com