Climate twins of Petaluma, CA
These are the US cities whose 12-month climate pattern most closely matches Petaluma'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: Petaluma vs its climate twin
Top match: Solvang, CA
| Month | Petaluma | Solvang | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 57.6°F | 39.0°F | 4.77 in | 67.2°F | 34.2°F | 4.89 in |
| February | 61.3°F | 40.4°F | 5.23 in | 68.1°F | 35.4°F | 5.29 in |
| March | 64.5°F | 41.9°F | 3.32 in | 71.2°F | 37.8°F | 3.61 in |
| April | 67.8°F | 43.8°F | 1.68 in | 75.7°F | 39.3°F | 1.31 in |
| May | 71.9°F | 47.4°F | 0.93 in | 79.8°F | 42.8°F | 0.54 in |
| June | 78.1°F | 50.4°F | 0.28 in | 86.2°F | 45.3°F | 0.06 in |
| July | 80.8°F | 52.4°F | 0.01 in | 92.1°F | 47.8°F | 0.01 in |
| August | 81.2°F | 52.8°F | 0.05 in | 93.2°F | 48.5°F | 0.00 in |
| September | 81.6°F | 51.4°F | 0.09 in | 90.6°F | 46.7°F | 0.08 in |
| October | 76.4°F | 47.6°F | 1.27 in | 84.2°F | 43.1°F | 0.80 in |
| November | 65.5°F | 42.3°F | 2.74 in | 74.8°F | 38.0°F | 1.24 in |
| December | 57.9°F | 38.4°F | 5.19 in | 66.8°F | 33.4°F | 3.30 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 →