Climate twins of Mason City, IL
These are the US cities whose 12-month climate pattern most closely matches Mason City'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: Mason City vs its climate twin
Top match: Wellington, IL
| Month | Mason City | Wellington | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 33.1°F | 16.2°F | 2.34 in | 33.5°F | 18.3°F | 2.12 in |
| February | 37.9°F | 19.4°F | 1.96 in | 38.3°F | 21.7°F | 1.96 in |
| March | 50.6°F | 29.5°F | 2.49 in | 50.4°F | 30.9°F | 2.82 in |
| April | 64.3°F | 41.2°F | 3.73 in | 63.9°F | 41.3°F | 3.95 in |
| May | 73.7°F | 52.8°F | 4.47 in | 74.3°F | 52.5°F | 4.78 in |
| June | 82.4°F | 61.8°F | 4.20 in | 82.7°F | 61.7°F | 4.89 in |
| July | 85.2°F | 64.6°F | 5.14 in | 84.8°F | 64.5°F | 4.59 in |
| August | 83.5°F | 62.1°F | 3.57 in | 83.4°F | 62.5°F | 3.96 in |
| September | 78.7°F | 53.9°F | 3.55 in | 78.6°F | 55.2°F | 3.36 in |
| October | 65.8°F | 42.9°F | 3.33 in | 65.6°F | 44.4°F | 3.43 in |
| November | 50.9°F | 30.5°F | 2.78 in | 50.4°F | 33.2°F | 2.91 in |
| December | 37.8°F | 21.7°F | 1.70 in | 38.1°F | 23.9°F | 2.12 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 →