Climate twins of Rock Island, WA

These are the US cities whose 12-month climate pattern most closely matches Rock Island'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
Adrian, OR
similarity distance: 0.741 (lower = more similar)
Rank 2 closest
Parma, ID
similarity distance: 0.741 (lower = more similar)
Rank 3 closest
Notus, ID
similarity distance: 0.741 (lower = more similar)

Side-by-side: Rock Island vs its climate twin

Top match: Adrian, OR

Month Rock Island Adrian
High Low Precip High Low Precip
January 33.6°F 24.1°F 1.02 in 37.4°F 22.7°F 1.33 in
February 41.6°F 27.4°F 0.76 in 45.7°F 26.0°F 0.81 in
March 52.5°F 33.7°F 0.73 in 56.9°F 31.3°F 0.88 in
April 61.8°F 40.4°F 0.57 in 64.2°F 36.4°F 0.89 in
May 71.6°F 48.7°F 0.77 in 73.3°F 45.7°F 1.37 in
June 78.2°F 54.9°F 0.50 in 81.4°F 51.7°F 0.78 in
July 87.6°F 61.8°F 0.24 in 92.4°F 57.0°F 0.25 in
August 86.4°F 61.0°F 0.23 in 91.3°F 54.6°F 0.19 in
September 76.7°F 52.5°F 0.23 in 81.6°F 46.1°F 0.64 in
October 60.5°F 40.9°F 0.62 in 66.3°F 35.7°F 0.73 in
November 43.8°F 30.9°F 0.85 in 48.9°F 28.0°F 0.99 in
December 33.4°F 24.5°F 1.31 in 38.2°F 22.7°F 1.12 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 →