Climate twins of Vallejo, CA
These are the US cities whose 12-month climate pattern most closely matches Vallejo's. Each "twin" must be at least 140 miles away to avoid trivial near-neighbor matches. Similarity is computed across all 24 monthly metrics (12 average temperatures + 12 average precipitations), normalized so temperature and precipitation contribute equally.
Side-by-side: Vallejo vs its climate twin
Top match: Santa Barbara, CA
| Month | Vallejo | Santa Barbara | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 57.3°F | 42.0°F | 4.46 in | 66.8°F | 46.5°F | 4.43 in |
| February | 63.1°F | 45.0°F | 3.58 in | 66.9°F | 47.3°F | 4.41 in |
| March | 68.4°F | 45.9°F | 3.18 in | 68.3°F | 49.4°F | 3.20 in |
| April | 72.7°F | 47.2°F | 1.45 in | 71.0°F | 51.4°F | 1.01 in |
| May | 78.4°F | 50.9°F | 0.80 in | 71.6°F | 54.3°F | 0.41 in |
| June | 83.1°F | 54.1°F | 0.22 in | 73.0°F | 57.3°F | 0.14 in |
| July | 85.4°F | 55.7°F | 0.00 in | 76.4°F | 60.2°F | 0.01 in |
| August | 86.0°F | 56.1°F | 0.04 in | 77.7°F | 60.3°F | 0.01 in |
| September | 86.1°F | 56.5°F | 0.08 in | 77.7°F | 59.5°F | 0.05 in |
| October | 79.0°F | 53.6°F | 1.02 in | 75.7°F | 56.0°F | 0.84 in |
| November | 65.5°F | 47.0°F | 2.17 in | 71.0°F | 50.2°F | 1.40 in |
| December | 57.6°F | 42.0°F | 4.49 in | 66.2°F | 46.1°F | 3.07 in |
How this is computed
Each city is represented by a 24-dimensional vector: 12 monthly average temperatures and 12 monthly average precipitations. Each dimension is z-score normalized across the population of US cities, so that temperature variance and precipitation variance contribute proportionally. Distance between cities is Euclidean. We filter out cities within 2° latitude/longitude (~140 miles) so that "twins" mean climatically similar but geographically distinct — not just the neighboring town. Full methodology →