St. Charles, IA
Climate overview — based on NOAA 1991-2020 normals from INDIANOLA 2W, IA US.
Year-round temperatures (°F)
Climate summary
St. Charles has an annual average temperature of 49.9°F with about 37.8 inches of precipitation per year and 30.8 inches of snow. The warmest month is July (average high 85.5°F), and the coldest is January (average low 11.6°F). June is typically the wettest month (5.72 in) and January the driest (0.91 in). Snow typically falls from October through May.
Best time to visit St. Charles
Full guide →Climate change signal
All-time records →20 of 366 (5.5%) of St. Charles's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1890s | 21 | |
| 1900s | 10 | |
| 1910s | 18 | |
| 1920s | 26 | |
| 1930s | 97 | |
| 1940s | 34 | |
| 1950s | 31 | |
| 1960s | 11 | |
| 1970s | 16 | |
| 1980s | 32 | |
| 1990s | 18 | |
| 2000s | 15 | |
| 2010s | 32 | |
| 2020s | 5 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 31.7°F | 11.6°F | 21.7°F | 0.91 in | 8.5 in | 5 |
| February | 36.3°F | 15.2°F | 25.8°F | 1.42 in | 8.2 in | 7 |
| March | 49.5°F | 27.1°F | 38.3°F | 1.94 in | 3.7 in | 7 |
| April | 62.1°F | 37.9°F | 50.0°F | 3.88 in | 1.0 in | 10 |
| May | 71.9°F | 49.9°F | 60.9°F | 5.58 in | 0.3 in | 12 |
| June | 81.4°F | 60.0°F | 70.7°F | 5.72 in | — | 11 |
| July | 85.5°F | 64.0°F | 74.7°F | 4.32 in | — | 8 |
| August | 84.0°F | 61.6°F | 72.8°F | 3.90 in | — | 9 |
| September | 77.6°F | 52.4°F | 65.0°F | 3.86 in | — | 8 |
| October | 64.8°F | 40.1°F | 52.5°F | 3.02 in | 0.5 in | 8 |
| November | 49.6°F | 27.9°F | 38.8°F | 1.85 in | 1.9 in | 6 |
| December | 36.9°F | 17.4°F | 27.1°F | 1.40 in | 6.7 in | 6 |
Climate twins of St. Charles
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).