Climate twins of Joliet, IL
These are the US cities whose 12-month climate pattern most closely matches Joliet'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: Joliet vs its climate twin
Top match: Poneto, IN
| Month | Joliet | Poneto | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 31.1°F | 16.6°F | 1.99 in | 31.9°F | 17.2°F | 2.51 in |
| February | 35.4°F | 19.8°F | 1.78 in | 35.6°F | 19.2°F | 1.96 in |
| March | 47.0°F | 29.2°F | 2.27 in | 46.7°F | 27.9°F | 2.65 in |
| April | 59.9°F | 38.9°F | 3.93 in | 59.9°F | 38.7°F | 3.83 in |
| May | 71.0°F | 49.4°F | 4.53 in | 71.1°F | 50.6°F | 4.67 in |
| June | 80.3°F | 59.9°F | 4.30 in | 79.6°F | 60.4°F | 4.71 in |
| July | 83.6°F | 64.1°F | 4.55 in | 82.6°F | 63.3°F | 4.46 in |
| August | 81.8°F | 62.9°F | 3.97 in | 80.9°F | 61.2°F | 3.84 in |
| September | 76.2°F | 55.3°F | 3.17 in | 75.6°F | 53.7°F | 3.07 in |
| October | 63.3°F | 43.4°F | 3.14 in | 63.2°F | 42.4°F | 2.92 in |
| November | 48.5°F | 32.3°F | 2.46 in | 48.9°F | 32.2°F | 3.08 in |
| December | 36.4°F | 22.4°F | 1.94 in | 37.2°F | 23.0°F | 2.33 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 →