Alton, MO
Climate overview — based on NOAA 1991-2020 normals from ALTON, MO US.
Year-round temperatures (°F)
Climate summary
Alton has an annual average temperature of 55.7°F with about 47.2 inches of precipitation per year and 4.2 inches of snow. The warmest month is July (average high 88.3°F), and the coldest is January (average low 22.4°F). May is typically the wettest month (5.57 in) and January the driest (2.96 in). Snow typically falls from December through March.
Best time to visit Alton
Full guide →Climate change signal
All-time records →31 of 366 (8.5%) of Alton'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.
| 1940s | 0 | |
| 1950s | 0 | |
| 1960s | 80 | |
| 1970s | 66 | |
| 1980s | 37 | |
| 1990s | 48 | |
| 2000s | 75 | |
| 2010s | 29 | |
| 2020s | 31 |
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 | 43.8°F | 22.4°F | 33.1°F | 2.96 in | 1.7 in | 6 |
| February | 48.6°F | 25.1°F | 36.9°F | 3.39 in | 0.8 in | 7 |
| March | 58.3°F | 33.7°F | 46.0°F | 4.45 in | 0.9 in | 9 |
| April | 68.7°F | 43.2°F | 56.0°F | 4.66 in | — | 8 |
| May | 75.8°F | 53.1°F | 64.5°F | 5.57 in | — | 10 |
| June | 85.0°F | 61.7°F | 73.4°F | 3.31 in | — | 7 |
| July | 88.3°F | 65.9°F | 77.1°F | 4.01 in | — | 7 |
| August | 88.1°F | 64.2°F | 76.1°F | 3.92 in | — | 7 |
| September | 80.8°F | 55.4°F | 68.1°F | 3.46 in | — | 5 |
| October | 70.2°F | 42.8°F | 56.5°F | 3.77 in | — | 6 |
| November | 56.7°F | 33.2°F | 45.0°F | 4.44 in | — | 7 |
| December | 45.9°F | 25.7°F | 35.8°F | 3.29 in | 0.8 in | 7 |
Climate twins of Alton
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).