Last updated: June 24, 2025
In April, the average temperature in Saint Charles, United States is a crisp 10°C (50°F). Be prepared for a range of weather, as temperatures can drop to a chilly -10°C (14°F) or rise to a balmy 30°C (86°F). With an average humidity of 77% and about 69 mm (2.7 in) of precipitation spread over 10 days, it's wise to expect a mix of sun and rain during your visit!
In April in Saint Charles, the average temperature is 10°C (50°F). The maximum can reach 30°C (86°F), and the minimum can be as low as -10°C (14°F). Be prepared for a wide range of temperatures when traveling, so pack accordingly!
In Saint Charles in April, the precipitation amount is 69 mm (2.7 in) spread over a period of 10 days.
In Saint Charles in April, humidity is 77%. With an average temperature of 10°C (50°F), this humidity feels like a thick, heavy blanket enveloping you, making travel uncomfortable and sticky, as it clings to your skin and clothes, turning each step into a challenge.
In Saint Charles in April, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Saint Charles.
UV Risk Categories
Weather in Saint Charles varies notably across the year, with each month offering distinct climate conditions. This page compares April’s weather to other months in Saint Charles, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -5°C (23°F) | 41 mm (1.6 inches) | 78% | moderate |
| February Weather | -4°C (25°F) | 39 mm (1.6 inches) | 80% | moderate |
| March Weather | 5°C (41°F) | 85 mm (3.3 inches) | 77% | high |
| April Weather | 10°C (50°F) | 69 mm (2.7 inches) | 77% | very high |
| May Weather | 17°C (63°F) | 163 mm (6.4 inches) | 77% | very high |
| June Weather | 24°C (75°F) | 117 mm (4.6 inches) | 81% | extreme |
| July Weather | 25°C (78°F) | 69 mm (2.7 inches) | 81% | very high |
| August Weather | 24°C (75°F) | 76 mm (3.0 inches) | 77% | very high |
| September Weather | 20°C (69°F) | 117 mm (4.6 inches) | 73% | very high |
| October Weather | 12°C (53°F) | 134 mm (5.3 inches) | 75% | high |
| November Weather | 4°C (39°F) | 43 mm (1.7 inches) | 85% | moderate |
| December Weather | 0°C (32°F) | 36 mm (1.4 inches) | 83% | moderate |