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.
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 ≈ 1.56 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
86.1° in September, 42° in January
Thirty-year averages, not a forecast. Any individual year can differ substantially.
| Month | High | Low | Rain |
|---|---|---|---|
| Jan | 57.3° | 42° | 4.46" |
| Feb | 63.1° | 45° | 3.58" |
| Mar | 68.4° | 45.9° | 3.18" |
| Apr | 72.7° | 47.2° | 1.45" |
| May | 78.4° | 50.9° | 0.8" |
| Jun | 83.1° | 54.1° | 0.22" |
| Jul | 85.4° | 55.7° | 0" |
| Aug | 86° | 56.1° | 0.04" |
| Sep | 86.1° | 56.5° | 0.08" |
| Oct | 79° | 53.6° | 1.02" |
| Nov | 65.5° | 47° | 2.17" |
| Dec | 57.6° | 42° | 4.49" |
This station records temperature and precipitation but not snowfall, so no snow column is shown. That is missing data, not a report of zero snow — Vallejo may well get plenty.
NOAA/NCEI 1991–2020 U.S. Climate Normals — station VALLEJO, CA US, 3.4 mi away.
Growing season zone 9b
346 frost-free days
Last spring frost around January 17, first fall frost around December 27. 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
- Nothing about a specific property — only the area around it.
- No flood zone, deliberately: that is parcel-level and this page would have to guess.
- Nothing about wildfire, radon, subsidence, soil or the building itself.
- Climate normals describe a typical year, not the year you are about to have.