Climate twins of Napoleon, OH

These are the US cities whose 12-month climate pattern most closely matches Napoleon'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: Napoleon vs its climate twin

Top match: Plymouth, IN

Month Napoleon Plymouth
High Low Precip High Low Precip
January 32.8°F 17.4°F 2.53 in 31.4°F 16.7°F 2.63 in
February 35.5°F 18.8°F 2.25 in 35.4°F 18.5°F 2.33 in
March 46.1°F 27.6°F 2.60 in 47.1°F 27.7°F 2.45 in
April 59.6°F 37.2°F 3.65 in 59.8°F 38.0°F 3.63 in
May 71.5°F 49.9°F 4.02 in 71.2°F 49.4°F 4.33 in
June 80.8°F 59.8°F 3.67 in 80.6°F 59.3°F 4.24 in
July 83.9°F 63.1°F 3.45 in 83.8°F 62.7°F 4.39 in
August 83.0°F 60.4°F 3.71 in 81.9°F 61.0°F 4.05 in
September 76.3°F 52.8°F 3.31 in 76.1°F 53.5°F 3.20 in
October 63.7°F 42.3°F 2.74 in 63.3°F 42.4°F 3.38 in
November 49.1°F 32.0°F 2.86 in 48.4°F 31.8°F 3.03 in
December 37.4°F 23.8°F 2.53 in 36.7°F 23.0°F 2.60 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 →