Climate twins of Grass Valley, OR

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

Top match: Alturas, CA

Month	Grass Valley			Alturas
	High	Low	Precip	High	Low	Precip
January	40.1°F	24.5°F	1.47 in	44.1°F	21.3°F	1.49 in
February	44.9°F	26.2°F	1.06 in	47.3°F	23.1°F	0.98 in
March	52.3°F	30.1°F	0.97 in	53.2°F	27.2°F	1.22 in
April	58.8°F	34.5°F	0.96 in	59.2°F	30.9°F	1.21 in
May	67.4°F	41.6°F	0.96 in	69.6°F	37.4°F	1.39 in
June	74.3°F	47.0°F	0.57 in	79.1°F	42.2°F	0.71 in
July	84.0°F	53.0°F	0.18 in	89.7°F	46.3°F	0.23 in
August	83.8°F	52.6°F	0.20 in	88.2°F	44.4°F	0.30 in
September	75.8°F	45.4°F	0.43 in	81.0°F	38.1°F	0.37 in
October	62.2°F	36.2°F	1.06 in	67.0°F	30.7°F	0.94 in
November	48.4°F	28.7°F	1.54 in	51.8°F	25.1°F	1.39 in
December	39.5°F	24.2°F	1.61 in	41.5°F	22.5°F	1.51 in

Cities that consider Grass Valley their climate twin

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

Alturas, CA (ranks Grass Valley #3)
Ritzville, WA (ranks Grass Valley #2)

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 →