Climate twins of Harlem, MT

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

Top match: Helena, MT

Month	Harlem			Helena
	High	Low	Precip	High	Low	Precip
January	28.2°F	5.0°F	0.51 in	32.4°F	13.5°F	0.39 in
February	32.7°F	8.9°F	0.36 in	37.2°F	17.2°F	0.42 in
March	45.0°F	19.9°F	0.52 in	47.5°F	24.6°F	0.52 in
April	58.8°F	29.9°F	1.00 in	56.7°F	32.4°F	1.02 in
May	69.0°F	39.7°F	1.89 in	66.4°F	41.5°F	1.95 in
June	76.6°F	48.7°F	2.90 in	74.7°F	48.7°F	2.21 in
July	85.0°F	53.5°F	1.44 in	86.1°F	55.1°F	1.06 in
August	84.7°F	51.6°F	0.99 in	84.6°F	52.9°F	1.04 in
September	74.1°F	41.7°F	1.09 in	73.3°F	44.6°F	0.96 in
October	59.7°F	30.4°F	0.73 in	57.6°F	33.5°F	0.78 in
November	43.3°F	18.9°F	0.57 in	42.8°F	22.8°F	0.59 in
December	30.9°F	8.7°F	0.50 in	32.6°F	14.2°F	0.46 in

Cities that consider Harlem their climate twin

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

Chester, MT (ranks Harlem #3)

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 →