Climate twins of Issaquah, WA

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

Top match: Hillsboro, OR

Month Issaquah Hillsboro
High Low Precip High Low Precip
January 48.0°F 37.1°F 4.93 in 47.3°F 33.6°F 5.27 in
February 50.4°F 36.9°F 3.21 in 51.0°F 33.5°F 3.97 in
March 54.7°F 39.5°F 3.74 in 55.9°F 36.5°F 3.70 in
April 59.5°F 43.1°F 2.83 in 60.9°F 39.2°F 2.57 in
May 66.3°F 48.9°F 1.86 in 68.7°F 44.7°F 2.02 in
June 71.0°F 53.6°F 1.47 in 73.5°F 48.6°F 1.31 in
July 77.2°F 57.5°F 0.60 in 82.1°F 52.2°F 0.37 in
August 77.6°F 57.4°F 0.89 in 82.4°F 51.8°F 0.48 in
September 71.6°F 53.1°F 1.53 in 76.4°F 47.5°F 1.38 in
October 61.0°F 46.4°F 3.49 in 63.7°F 40.9°F 3.37 in
November 52.4°F 40.1°F 5.61 in 52.6°F 36.5°F 5.44 in
December 47.0°F 36.6°F 4.53 in 46.2°F 33.3°F 6.05 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 →