Climate twins of Chain of Rocks, MO

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

Top match: Mason, IL

Month Chain of Rocks Mason
High Low Precip High Low Precip
January 39.3°F 21.2°F 2.44 in 37.4°F 20.1°F 2.93 in
February 44.9°F 24.8°F 2.37 in 42.5°F 23.4°F 2.44 in
March 55.5°F 33.3°F 3.46 in 53.5°F 32.4°F 3.30 in
April 67.3°F 43.3°F 4.74 in 65.9°F 42.4°F 4.84 in
May 76.3°F 53.5°F 4.80 in 76.2°F 53.6°F 5.27 in
June 84.4°F 63.3°F 4.26 in 85.1°F 62.8°F 4.87 in
July 88.1°F 67.5°F 4.23 in 88.5°F 66.0°F 4.29 in
August 87.2°F 65.4°F 3.76 in 87.2°F 63.7°F 3.19 in
September 80.8°F 57.1°F 3.07 in 81.2°F 55.5°F 2.89 in
October 68.5°F 45.2°F 3.11 in 68.8°F 44.1°F 3.49 in
November 54.9°F 35.0°F 3.54 in 54.0°F 33.7°F 3.73 in
December 43.6°F 26.5°F 2.56 in 42.2°F 25.4°F 2.77 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 →