Climate twins of Napa, CA

These are the US cities whose 12-month climate pattern most closely matches Napa'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.

Rank 1 closest
Solvang, CA
similarity distance: 1.844 (lower = more similar)
Rank 2 closest
Ojai, CA
similarity distance: 2.080 (lower = more similar)
Rank 3 closest
Santa Barbara, CA
similarity distance: 2.365 (lower = more similar)

Side-by-side: Napa vs its climate twin

Top match: Solvang, CA

Month Napa Solvang
High Low Precip High Low Precip
January 58.6°F 40.1°F 4.98 in 67.2°F 34.2°F 4.89 in
February 63.2°F 41.9°F 5.13 in 68.1°F 35.4°F 5.29 in
March 67.5°F 43.6°F 3.67 in 71.2°F 37.8°F 3.61 in
April 72.1°F 45.6°F 1.72 in 75.7°F 39.3°F 1.31 in
May 76.6°F 49.9°F 1.08 in 79.8°F 42.8°F 0.54 in
June 82.3°F 53.7°F 0.29 in 86.2°F 45.3°F 0.06 in
July 83.3°F 55.5°F 0.00 in 92.1°F 47.8°F 0.01 in
August 83.7°F 55.5°F 0.06 in 93.2°F 48.5°F 0.00 in
September 84.4°F 53.4°F 0.09 in 90.6°F 46.7°F 0.08 in
October 78.1°F 49.3°F 1.34 in 84.2°F 43.1°F 0.80 in
November 66.2°F 43.6°F 2.77 in 74.8°F 38.0°F 1.24 in
December 58.5°F 39.7°F 5.53 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 →