Address reportCitiesCalifornia › San Francisco

San Francisco, CA

Earthquake hazard, typical weather and growing season from public federal data. Population 837,442.

Flood zone: it depends on the exact parcel

There is no such thing as a flood zone for a whole city. Two houses on the same street can sit in different zones, and it is the single fact here that changes most over a short distance. So this page does not guess one.

Look up a specific San Francisco address →

Earthquake hazard very-high

Design category D

Very high seismic hazard — at or near a major active fault. Very strong ground shaking is likely and the most stringent seismic-design provisions apply. A site-specific ground-motion study is typically required. The ASCE 7 Seismic Design Category here is D. (Short-period design value Ss ≈ 1.5 g — the standard headline measure of ground-shaking hazard.)

USGS Seismic Design Web Services (ASCE 7), assuming Site Class D — stiff or unknown soil. Real soil conditions can move the category either way.

Typical weather

66.4° in October, 45.7° in January

Thirty-year averages, not a forecast. Any individual year can differ substantially.

MonthHighLowRainSnow
Jan59°45.7°3.94"0"
Feb60.4°46.6°4.01"0"
Mar60.8°47.9°2.98"0"
Apr60.4°49.1°1.37"0"
May59.8°51°0.64"0"
Jun60.9°52.7°0.19"0"
Jul61.8°54.3°0.01"0"
Aug63.7°55.4°0.05"0"
Sep65°55.3°0.11"0"
Oct66.4°53.2°0.9"0"
Nov63.5°49.5°2.22"0"
Dec59.1°45.8°4.22"0"

NOAA/NCEI 1991–2020 U.S. Climate Normals — station SAN FRANCISCO OCEANSIDE, CA US, 4.3 mi away.

Growing season zone 10b

365 frost-free days

Last spring frost around n/a, first fall frost around n/a. Roughly half of years see frost outside that window.

2023 USDA Plant Hardiness Zone Map and NOAA/NCEI 1991–2020 frost normals.

What this page does not tell you

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