Santa Rosa, California vs Castro Valley Climate
90%matchSanta Rosa and Castro Valley are a 90% climate match. Compared with Santa Rosa, Castro Valley has half the winter rain, 5°F (3°C) cooler summer days and 4°F (2°C) milder winter nights.
Santa Rosa gets 32 in (822 mm) of rain a year and Castro Valley 17 in (441 mm). Santa Rosa's warmest month is July, at 85°F (29°C); Castro Valley's is September, at 81°F (27°C).
Climate fingerprints: ring color = average temperature, thickness = rain. January at the top.
Month by month
Highs and lows (°F)
Santa RosaCastro Valleysolid = high, dashed = low
Rain (in per month)
Santa RosaCastro Valley
Monthly averages
| Month | High | Low | Rain | |||
|---|---|---|---|---|---|---|
| Santa Rosa | Castro Valley | Santa Rosa | Castro Valley | Santa Rosa | Castro Valley | |
| Jan | 59°F(15°C) | 59°F(15°C) | 40°F(4°C) | 43°F(6°C) | 6.3 in(160 mm) | 3.5 in(89 mm) |
| Feb | 64°F(18°C) | 63°F(17°C) | 41°F(5°C) | 45°F(7°C) | 6.5 in(165 mm) | 3.3 in(83 mm) |
| Mar | 66°F(19°C) | 66°F(19°C) | 43°F(6°C) | 47°F(8°C) | 4.6 in(116 mm) | 2.5 in(63 mm) |
| Apr | 71°F(22°C) | 70°F(21°C) | 44°F(7°C) | 48°F(9°C) | 1.9 in(48 mm) | 1.3 in(33 mm) |
| May | 76°F(25°C) | 73°F(23°C) | 48°F(9°C) | 51°F(11°C) | 1.2 in(31 mm) | 0.6 in(14 mm) |
| Jun | 83°F(28°C) | 78°F(25°C) | 52°F(11°C) | 55°F(13°C) | 0.3 in(8 mm) | 0.2 in(4 mm) |
| Jul | 85°F(29°C) | 79°F(26°C) | 53°F(11°C) | 56°F(14°C) | 0.0 in(1 mm) | 0.0 in(1 mm) |
| Aug | 85°F(29°C) | 80°F(27°C) | 53°F(12°C) | 57°F(14°C) | 0.1 in(2 mm) | 0.0 in(1 mm) |
| Sep | 85°F(29°C) | 81°F(27°C) | 52°F(11°C) | 56°F(13°C) | 0.2 in(4 mm) | 0.1 in(2 mm) |
| Oct | 79°F(26°C) | 76°F(25°C) | 47°F(8°C) | 52°F(11°C) | 1.7 in(43 mm) | 1.0 in(26 mm) |
| Nov | 67°F(20°C) | 67°F(19°C) | 42°F(5°C) | 47°F(8°C) | 3.4 in(87 mm) | 1.9 in(47 mm) |
| Dec | 59°F(15°C) | 60°F(16°C) | 38°F(4°C) | 43°F(6°C) | 6.2 in(157 mm) | 3.1 in(78 mm) |
1991–2020 averages, by calendar month.