Climate twins of Thomson, IL
These are the US cities whose 12-month climate pattern most closely matches Thomson'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: Thomson vs its climate twin
Top match: Buffalo Grove, IL
| Month | Thomson | Buffalo Grove | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 29.3°F | 13.6°F | 1.40 in | 31.9°F | 18.4°F | 1.33 in |
| February | 33.8°F | 17.1°F | 1.56 in | 35.8°F | 21.2°F | 1.28 in |
| March | 45.7°F | 28.2°F | 2.41 in | 46.7°F | 30.2°F | 1.84 in |
| April | 59.4°F | 39.8°F | 3.39 in | 58.1°F | 39.3°F | 3.31 in |
| May | 71.1°F | 51.4°F | 4.03 in | 69.5°F | 49.7°F | 3.76 in |
| June | 80.7°F | 61.7°F | 4.52 in | 79.5°F | 60.1°F | 3.97 in |
| July | 84.0°F | 65.2°F | 3.40 in | 84.0°F | 65.8°F | 3.15 in |
| August | 82.1°F | 63.2°F | 3.43 in | 82.0°F | 64.7°F | 3.70 in |
| September | 75.9°F | 55.2°F | 3.66 in | 75.3°F | 56.3°F | 3.04 in |
| October | 63.0°F | 43.4°F | 2.58 in | 62.5°F | 44.5°F | 3.11 in |
| November | 47.6°F | 31.4°F | 2.20 in | 48.5°F | 33.4°F | 2.15 in |
| December | 34.8°F | 20.5°F | 1.69 in | 36.9°F | 24.0°F | 1.64 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 →