Climate twins of Monmouth, IL

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

Top match: Seneca, IL

Month Monmouth Seneca
High Low Precip High Low Precip
January 31.4°F 14.7°F 1.85 in 31.4°F 14.2°F 1.95 in
February 36.2°F 18.7°F 1.98 in 35.4°F 17.2°F 1.90 in
March 49.7°F 29.1°F 2.61 in 47.5°F 27.2°F 2.54 in
April 62.8°F 39.7°F 3.95 in 61.2°F 37.3°F 3.59 in
May 72.9°F 50.9°F 5.18 in 72.6°F 48.5°F 4.70 in
June 81.2°F 60.3°F 4.53 in 81.1°F 58.1°F 4.92 in
July 84.1°F 63.6°F 3.96 in 84.0°F 61.9°F 3.85 in
August 82.8°F 61.5°F 3.92 in 82.4°F 60.5°F 4.09 in
September 77.3°F 53.6°F 3.70 in 77.1°F 52.9°F 3.46 in
October 64.8°F 42.2°F 3.01 in 64.1°F 41.2°F 3.20 in
November 49.2°F 30.6°F 2.58 in 49.1°F 30.0°F 2.72 in
December 36.5°F 20.8°F 2.15 in 36.6°F 20.5°F 2.11 in

Cities that consider Monmouth their climate twin

These US cities have Monmouth in their top 3 most-similar list — meaning if you were to move from any of these places, Monmouth 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 →