Climate twins of Rock Island, IL
These are the US cities whose 12-month climate pattern most closely matches Rock 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: Rock Island vs its climate twin
Top match: South Gifford, MO
| Month | Rock Island | South Gifford | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 31.8°F | 14.8°F | 1.66 in | 34.4°F | 17.2°F | 1.60 in |
| February | 36.6°F | 18.8°F | 1.83 in | 39.5°F | 20.6°F | 1.77 in |
| March | 49.9°F | 29.6°F | 2.62 in | 51.8°F | 30.6°F | 2.62 in |
| April | 63.0°F | 39.9°F | 3.81 in | 63.3°F | 41.0°F | 3.93 in |
| May | 73.9°F | 51.1°F | 4.67 in | 72.4°F | 51.7°F | 5.02 in |
| June | 83.1°F | 61.0°F | 5.01 in | 81.9°F | 61.3°F | 5.07 in |
| July | 86.1°F | 64.9°F | 4.23 in | 85.8°F | 65.0°F | 4.35 in |
| August | 84.1°F | 62.7°F | 3.97 in | 84.4°F | 62.8°F | 3.94 in |
| September | 77.9°F | 54.2°F | 3.32 in | 77.1°F | 53.9°F | 3.65 in |
| October | 64.8°F | 42.6°F | 2.81 in | 64.5°F | 43.2°F | 3.24 in |
| November | 49.8°F | 30.9°F | 2.30 in | 50.9°F | 31.2°F | 2.41 in |
| December | 37.0°F | 20.8°F | 2.04 in | 39.1°F | 22.1°F | 1.67 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 →