Climate twins of Promise City, IA
These are the US cities whose 12-month climate pattern most closely matches Promise 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: Promise City vs its climate twin
Top match: Muscatine, IA
| Month | Promise City | Muscatine | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 31.5°F | 12.8°F | 1.06 in | 31.0°F | 13.1°F | 1.51 in |
| February | 36.7°F | 16.5°F | 1.52 in | 35.9°F | 17.4°F | 1.78 in |
| March | 49.2°F | 27.7°F | 2.38 in | 49.5°F | 28.4°F | 2.55 in |
| April | 61.5°F | 38.3°F | 4.01 in | 63.1°F | 39.4°F | 3.82 in |
| May | 71.1°F | 50.1°F | 5.65 in | 73.6°F | 50.9°F | 5.11 in |
| June | 80.1°F | 60.0°F | 5.14 in | 82.3°F | 60.8°F | 5.46 in |
| July | 84.8°F | 64.3°F | 4.73 in | 85.4°F | 64.2°F | 4.25 in |
| August | 82.9°F | 62.0°F | 4.86 in | 83.3°F | 62.0°F | 4.26 in |
| September | 75.9°F | 53.5°F | 4.20 in | 77.6°F | 53.7°F | 3.91 in |
| October | 63.5°F | 41.4°F | 3.09 in | 64.5°F | 41.8°F | 3.04 in |
| November | 48.8°F | 28.4°F | 2.15 in | 49.0°F | 29.6°F | 2.28 in |
| December | 36.6°F | 18.5°F | 1.62 in | 36.1°F | 19.5°F | 2.00 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 →