Climate twins of Castana, IA

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

Top match: Fennimore, WI

Month Castana Fennimore
High Low Precip High Low Precip
January 28.6°F 10.3°F 0.63 in 28.7°F 10.2°F 0.98 in
February 33.4°F 14.3°F 0.71 in 33.9°F 13.6°F 0.96 in
March 46.8°F 25.5°F 1.69 in 46.6°F 25.4°F 1.91 in
April 59.8°F 36.6°F 3.32 in 60.6°F 35.8°F 3.64 in
May 70.6°F 49.4°F 4.66 in 72.3°F 46.8°F 4.35 in
June 80.2°F 59.7°F 4.84 in 81.2°F 56.9°F 5.15 in
July 83.7°F 63.7°F 4.02 in 84.4°F 61.2°F 3.84 in
August 81.6°F 61.1°F 4.23 in 83.1°F 59.3°F 4.07 in
September 75.3°F 52.6°F 3.05 in 75.8°F 50.6°F 3.37 in
October 62.7°F 39.6°F 2.43 in 62.5°F 38.3°F 2.48 in
November 46.5°F 26.3°F 1.50 in 47.0°F 27.7°F 1.87 in
December 33.0°F 16.1°F 1.03 in 34.3°F 17.0°F 1.32 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 →