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.
Typical weather
82.8° in August, 41.3° in December
Thirty-year averages, not a forecast. Any individual year can differ substantially.
| Month | High | Low | Rain | Snow |
|---|---|---|---|---|
| Jan | 53.7° | 41.7° | 5.06" | 0.1" |
| Feb | 54.6° | 41.7° | 4.9" | 0.5" |
| Mar | 57.9° | 42.9° | 3.69" | 0.1" |
| Apr | 62° | 44.4° | 1.92" | 0" |
| May | 67.8° | 49.3° | 1.13" | 0" |
| Jun | 75.9° | 55.4° | 0.27" | 0" |
| Jul | 82.5° | 61.5° | 0.01" | 0" |
| Aug | 82.8° | 61° | 0.03" | 0" |
| Sep | 80° | 59.7° | 0.12" | 0" |
| Oct | 71.7° | 54° | 1.19" | 0" |
| Nov | 60.4° | 46.2° | 2.65" | 0" |
| Dec | 53.4° | 41.3° | 5.08" | 0" |
NOAA/NCEI 1991–2020 U.S. Climate Normals — station MT DIABLO JUNCTION, CA US, 8.1 mi away.
Growing season zone 9b
282 frost-free days
Last spring frost around March 8, first fall frost around December 22. 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.