Climate twins of Decorah, IA
These are the US cities whose 12-month climate pattern most closely matches Decorah'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: Decorah vs its climate twin
Top match: Casey, IA
| Month | Decorah | Casey | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 27.7°F | 10.4°F | 1.01 in | 29.7°F | 9.6°F | 0.89 in |
| February | 32.8°F | 14.0°F | 1.10 in | 34.6°F | 13.8°F | 1.18 in |
| March | 46.2°F | 25.9°F | 2.05 in | 47.5°F | 25.5°F | 1.88 in |
| April | 61.3°F | 37.3°F | 3.95 in | 61.0°F | 36.3°F | 4.11 in |
| May | 72.5°F | 48.4°F | 4.94 in | 71.8°F | 48.4°F | 5.30 in |
| June | 81.4°F | 58.6°F | 6.13 in | 81.7°F | 59.0°F | 5.23 in |
| July | 84.4°F | 62.6°F | 4.42 in | 85.1°F | 63.0°F | 4.32 in |
| August | 82.7°F | 60.7°F | 4.39 in | 82.7°F | 59.8°F | 4.52 in |
| September | 76.4°F | 52.3°F | 3.60 in | 76.6°F | 50.4°F | 3.61 in |
| October | 63.2°F | 40.4°F | 2.66 in | 63.6°F | 37.7°F | 2.81 in |
| November | 46.6°F | 28.4°F | 2.05 in | 47.7°F | 26.0°F | 1.88 in |
| December | 32.9°F | 17.4°F | 1.31 in | 34.9°F | 15.6°F | 1.41 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 →