Climate twins of Piedmont, SD

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

Top match: Gillette, WY

Month Piedmont Gillette
High Low Precip High Low Precip
January 36.9°F 13.2°F 0.24 in 36.2°F 15.8°F 0.59 in
February 37.8°F 14.5°F 0.44 in 37.6°F 16.8°F 0.78 in
March 46.7°F 22.6°F 0.88 in 48.7°F 24.8°F 1.13 in
April 54.4°F 31.0°F 1.99 in 56.4°F 31.7°F 2.13 in
May 64.4°F 41.6°F 3.73 in 65.9°F 41.0°F 3.27 in
June 75.4°F 51.6°F 2.95 in 77.0°F 50.2°F 2.54 in
July 83.6°F 58.2°F 2.68 in 86.4°F 57.0°F 1.68 in
August 82.7°F 56.3°F 1.97 in 85.4°F 55.7°F 1.38 in
September 73.9°F 46.9°F 1.48 in 75.3°F 46.4°F 1.25 in
October 59.3°F 34.9°F 1.60 in 59.2°F 34.4°F 1.57 in
November 47.3°F 23.5°F 0.51 in 46.2°F 24.1°F 0.63 in
December 38.6°F 15.4°F 0.31 in 35.8°F 16.1°F 0.64 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 →