Climate twins of Mercer Island, WA
These are the US cities whose 12-month climate pattern most closely matches Mercer Island'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: Mercer Island vs its climate twin
Top match: Hillsboro, OR
| Month | Mercer Island | Hillsboro | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 48.6°F | 36.8°F | 5.21 in | 47.3°F | 33.6°F | 5.27 in |
| February | 50.7°F | 36.8°F | 3.71 in | 51.0°F | 33.5°F | 3.97 in |
| March | 54.8°F | 39.4°F | 3.94 in | 55.9°F | 36.5°F | 3.70 in |
| April | 59.8°F | 43.6°F | 2.89 in | 60.9°F | 39.2°F | 2.57 in |
| May | 66.5°F | 49.3°F | 1.98 in | 68.7°F | 44.7°F | 2.02 in |
| June | 71.2°F | 54.0°F | 1.22 in | 73.5°F | 48.6°F | 1.31 in |
| July | 77.3°F | 57.5°F | 0.56 in | 82.1°F | 52.2°F | 0.37 in |
| August | 77.4°F | 58.1°F | 0.83 in | 82.4°F | 51.8°F | 0.48 in |
| September | 71.7°F | 53.9°F | 1.37 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 | 53.0°F | 39.9°F | 5.80 in | 52.6°F | 36.5°F | 5.44 in |
| December | 47.8°F | 36.2°F | 5.49 in | 46.2°F | 33.3°F | 6.05 in |
Cities that consider Mercer Island their climate twin
These US cities have Mercer Island in their top 3 most-similar list — meaning if you were to move from any of these places, Mercer Island would feel familiar.
- Hillsboro, OR (ranks Mercer Island #2)
- Amity, OR (ranks Mercer Island #2)
- Dayton, OR (ranks Mercer Island #2)
- Maywood Park, OR (ranks Mercer Island #2)
- Portland, OR (ranks Mercer Island #2)
- Riddle, OR (ranks Mercer Island #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 →