Climate twins of Grass Valley, CA

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: Dunsmuir, CA

Month	Grass Valley			Dunsmuir
	High	Low	Precip	High	Low	Precip
January	53.6°F	33.1°F	9.30 in	48.6°F	29.9°F	11.08 in
February	54.9°F	34.2°F	8.98 in	52.4°F	30.8°F	10.46 in
March	57.9°F	37.0°F	8.16 in	57.2°F	33.4°F	9.20 in
April	62.7°F	40.0°F	4.43 in	63.3°F	37.1°F	4.90 in
May	70.8°F	46.8°F	2.48 in	72.8°F	44.1°F	2.83 in
June	80.2°F	52.6°F	0.74 in	81.2°F	50.2°F	1.33 in
July	88.0°F	58.2°F	0.00 in	89.9°F	54.0°F	0.15 in
August	87.4°F	56.8°F	0.11 in	89.1°F	51.5°F	0.20 in
September	82.3°F	52.1°F	0.44 in	83.5°F	46.2°F	0.68 in
October	72.1°F	44.2°F	2.56 in	70.9°F	39.3°F	3.04 in
November	59.8°F	37.1°F	5.52 in	56.3°F	33.6°F	6.89 in
December	52.6°F	32.6°F	10.48 in	47.7°F	30.1°F	12.57 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.

Dunsmuir, CA (ranks Grass Valley #1)
Cave Junction, OR (ranks Grass Valley #2)
Willits, CA (ranks Grass Valley #3)
Scotts Valley, CA (ranks Grass Valley #1)

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 →