Climate twins of Union, IL

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

Top match: Williamsburg, IA

Month Union Williamsburg
High Low Precip High Low Precip
January 29.2°F 12.7°F 1.67 in 28.4°F 10.4°F 1.16 in
February 33.2°F 15.8°F 1.64 in 33.0°F 14.3°F 1.46 in
March 44.9°F 25.9°F 2.08 in 46.5°F 25.8°F 2.19 in
April 58.6°F 36.2°F 3.81 in 60.4°F 36.4°F 3.92 in
May 70.2°F 47.2°F 4.57 in 71.3°F 48.9°F 4.85 in
June 79.9°F 57.2°F 4.62 in 80.5°F 59.4°F 4.80 in
July 83.5°F 61.7°F 4.05 in 84.0°F 62.6°F 4.32 in
August 81.8°F 59.6°F 4.22 in 82.1°F 59.7°F 4.47 in
September 75.4°F 51.8°F 3.68 in 76.3°F 50.7°F 3.80 in
October 62.4°F 39.9°F 2.98 in 63.0°F 38.6°F 2.83 in
November 46.9°F 29.1°F 2.35 in 47.3°F 26.9°F 2.20 in
December 34.5°F 18.5°F 1.94 in 34.2°F 16.3°F 1.69 in

Cities that consider Union their climate twin

These US cities have Union in their top 3 most-similar list — meaning if you were to move from any of these places, Union would feel familiar.

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 →