Climate twins of Petersburg, IL
These are the US cities whose 12-month climate pattern most closely matches Petersburg'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: Petersburg vs its climate twin
Top match: Newark, MO
| Month | Petersburg | Newark | ||||
|---|---|---|---|---|---|---|
| High | Low | Precip | High | Low | Precip | |
| January | 34.4°F | 17.3°F | 2.02 in | 34.5°F | 17.8°F | 1.70 in |
| February | 39.3°F | 20.5°F | 1.75 in | 39.5°F | 21.5°F | 1.85 in |
| March | 50.8°F | 30.3°F | 2.51 in | 52.1°F | 31.5°F | 2.49 in |
| April | 63.7°F | 41.3°F | 4.09 in | 64.1°F | 42.0°F | 4.01 in |
| May | 73.7°F | 53.3°F | 4.61 in | 73.2°F | 52.8°F | 5.06 in |
| June | 82.2°F | 62.3°F | 4.14 in | 81.9°F | 62.2°F | 4.84 in |
| July | 85.5°F | 65.4°F | 3.87 in | 85.7°F | 65.5°F | 3.98 in |
| August | 84.5°F | 62.7°F | 3.66 in | 84.3°F | 63.5°F | 3.88 in |
| September | 78.8°F | 54.9°F | 3.12 in | 77.7°F | 55.0°F | 3.73 in |
| October | 66.3°F | 43.0°F | 3.19 in | 65.6°F | 44.1°F | 3.41 in |
| November | 51.5°F | 32.1°F | 2.76 in | 50.9°F | 32.6°F | 2.61 in |
| December | 39.1°F | 22.6°F | 1.93 in | 38.6°F | 23.3°F | 1.91 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 →