Climate twins of Piedmont, CA
These are the US cities whose 12-month climate pattern most closely matches Piedmont'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: Piedmont vs its climate twin
Top match: San Luis Obispo, CA
| Month | Piedmont | San Luis Obispo | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 59.8°F | 45.1°F | 4.35 in | 65.0°F | 40.6°F | 3.86 in |
| February | 62.4°F | 47.1°F | 4.35 in | 65.1°F | 42.4°F | 3.54 in |
| March | 64.7°F | 48.7°F | 3.21 in | 66.7°F | 44.5°F | 3.17 in |
| April | 66.8°F | 50.3°F | 1.37 in | 69.1°F | 45.6°F | 1.05 in |
| May | 68.6°F | 52.9°F | 0.75 in | 72.0°F | 47.8°F | 0.47 in |
| June | 71.8°F | 55.0°F | 0.20 in | 75.2°F | 51.1°F | 0.10 in |
| July | 71.6°F | 56.6°F | 0.00 in | 78.0°F | 54.3°F | 0.08 in |
| August | 72.8°F | 57.6°F | 0.05 in | 79.3°F | 54.9°F | 0.01 in |
| September | 74.6°F | 57.2°F | 0.10 in | 79.5°F | 53.4°F | 0.04 in |
| October | 72.7°F | 54.6°F | 1.13 in | 77.2°F | 49.7°F | 0.92 in |
| November | 65.8°F | 49.4°F | 2.44 in | 71.1°F | 44.7°F | 1.43 in |
| December | 59.7°F | 45.1°F | 4.66 in | 64.9°F | 40.2°F | 3.27 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 →