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April Weather in Alton, United States

Last updated: June 24, 2025

In April, the average temperature in Alton, United States hovers around 12°C (55°F), offering a delightful climate for visitors. Expect temperatures to vary widely, with minimums dipping to a chilly -5°C (23°F) and maximums reaching a warm 30°C (86°F). Precipitation is moderate, with an average of 123 mm (4.9 in) spread across 11 days, contributing to an average humidity of 80%.

April Temperature in Alton

In April in Alton, the average temperature is 12°C (55°F). Maximum temperatures can reach up to 30°C (86°F), while minimums can drop as low as -5°C (23°F). This range makes Alton an ideal destination for travelers seeking both warm days and cool evenings.

April Weather in Alton: Daily Temperature Highs, Lows, and Averages

The chart illustrates April temperature patterns in Alton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Alton, April typically has an average temperature of 12°C (55°F), with highs reaching up to 30°C (86°F) and lows dropping to around -5°C (23°F).
JanFebMarAprMayJunJulAugSepOctNovDec313446546776797672584338
Data source: Temperature data for Alton generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

April Precipitation in Alton

In Alton in April, the precipitation amount reaches 123 mm (4.9 in) over the course of 11 days.

April Precipitation Trends in Alton

The chart displays monthly precipitation patterns in Alton, with values for each month alongside April’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April’s conditions compare to those of other months. In Alton, April typically receives around 123 mm (4.9 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec737813212315010196119671007054
Data source: Precipitation data for April generated using information from the Copernicus Climate Change Service.
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April Humidity in Alton

In Alton in April, humidity is 80%. With an average temperature of 12°C (55°F), this humidity feels like a damp blanket wrapping around you, making it essential to choose breathable clothing and stay hydrated while exploring the area.

April Average Humidity in Alton

This chart illustrates the average monthly humidity levels in Alton, with April’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In April, average humidity in Alton is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%80%82%83%81%80%76%76%85%86%
Data source: Humidity data for April generated using information from the Copernicus Climate Change Service.

April UV Index in Alton

In Alton in April, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Alton.

Maximum UV Index Levels in Alton for April

The chart shows the monthly maximum UV Index (UVI) for Alton in April, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In April, the maximum UV index in Alton typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910111199643
Data source: Alton April UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How April Weather in Alton Compares to Other Months

Weather in Alton varies notably across the year, with each month offering distinct climate conditions. This page compares April’s weather to other months in Alton, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Alton, showing how April’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (32°F)73 mm (2.9 inches)82%moderate
February Weather1°C (35°F)78 mm (3.1 inches)80%moderate
March Weather8°C (46°F)132 mm (5.2 inches)80%high
April Weather12°C (55°F)123 mm (4.9 inches)80%very high
May Weather19°C (67°F)150 mm (5.9 inches)82%very high
June Weather25°C (77°F)101 mm (4.0 inches)83%extreme
July Weather26°C (79°F)96 mm (3.8 inches)81%extreme
August Weather24°C (76°F)119 mm (4.7 inches)80%very high
September Weather22°C (72°F)67 mm (2.6 inches)76%very high
October Weather15°C (59°F)100 mm (3.9 inches)76%high
November Weather6°C (44°F)70 mm (2.8 inches)85%moderate
December Weather3°C (38°F)54 mm (2.1 inches)86%moderate

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