Climate twins of Lerna, IL
These are the US cities whose 12-month climate pattern most closely matches Lerna'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: Lerna vs its climate twin
Top match: Perry, IL
| Month | Lerna | Perry | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 35.4°F | 20.3°F | 2.04 in | 36.5°F | 17.8°F | 1.96 in |
| February | 40.3°F | 23.7°F | 1.81 in | 41.6°F | 21.7°F | 2.00 in |
| March | 52.2°F | 33.0°F | 2.22 in | 52.8°F | 31.3°F | 2.57 in |
| April | 64.0°F | 43.2°F | 4.14 in | 65.0°F | 41.8°F | 3.92 in |
| May | 73.9°F | 54.0°F | 3.86 in | 74.9°F | 53.3°F | 4.41 in |
| June | 82.7°F | 62.8°F | 4.72 in | 83.8°F | 62.2°F | 4.75 in |
| July | 85.6°F | 65.7°F | 3.96 in | 87.3°F | 65.1°F | 4.48 in |
| August | 84.2°F | 63.5°F | 2.42 in | 86.1°F | 62.7°F | 3.21 in |
| September | 78.7°F | 56.1°F | 2.85 in | 79.9°F | 54.2°F | 3.59 in |
| October | 65.9°F | 45.3°F | 3.11 in | 67.5°F | 42.7°F | 3.10 in |
| November | 51.3°F | 34.6°F | 3.03 in | 53.3°F | 32.8°F | 2.82 in |
| December | 40.0°F | 26.0°F | 1.84 in | 41.2°F | 23.2°F | 2.26 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 →