Alton, IL weather and climate in 2024
Day
5 °C
Night
-4 °C
Sea
0 °C
Precipitation
74 mm
in month
Rainy days
8 days
in month
Daylight
9 hours
average
Sunshine
4 hours
average
Humidity
76 %
Day
5 °C
Night
-4 °C
Sea
0 °C
Precipitation
74 mm
in month
Rainy days
8 days
in month
Daylight
9 hours
average
Sunshine
4 hours
average
Humidity
76 %
Overview: Alton, IL
Weather charts for Alton, IL
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Weather overview for Alton, IL
Weather overview
Alton, IL, is known for its continental climate, with hot summers and chilly winters. During the warmest month, the day temperature peaks around 31 °C (88 °F), while January brings the lowest daytime highs near 4 °C (38 °F). The wettest month sees an average precipitation of approximately 114 mm (4.47 in), and even in the driest month, you can expect up to 54 mm (2.11 in) of rainfall. The terrain and weather in Alton can vary significantly, so be sure to pack layers and plan for sudden weather changes.
January weather
January in Alton, IL greets residents with brisk winter air. Daytime temperatures hover around 4 °C (38 °F), while at night they can plunge to an average low of -6 °C (21 °F). The number of wet days is relatively low with an average of 7 days, but one should always be prepared for snowfall and icy conditions.
February weather
As we move into February, the weather in Alton, IL remains chilly with an average daytime high of 6 °C (44 °F). Night temperatures still require a warm coat, averaging about -4 °C (24 °F). Though winter's grip persists, one can notice the days slowly getting longer, offering more sunshine and a hint of the upcoming spring.
March weather
March marks the transition towards spring in Alton, IL. Average daytime temperatures rise to 13 °C (55 °F), and the likelihood of rain increases, as evidenced by the average of 10 days of wet weather. With the increase in sunshine hours, Alton's landscapes begin to bloom, bringing a sense of renewal to the area.
April weather
April showers are in full swing in Alton, IL, priming the ground for May flowers. The temperatures continue to climb, reaching an average high of 19 °C (66 °F), but the increased rainfall of 97 mm (3.84 in) can lead to damp and unpredictable conditions.
May weather
May in Alton, IL sees the full swing of spring with warmer temperatures averaging 24 °C (75 °F) during the day. With 12 days of wet conditions, May is a vibrant month filled with greenery, but anticipatory of the summer heat to come.
June weather
June in Alton, IL ushers in the beginning of the hot summer months, with temperatures soaring to an average high of 29 °C (84 °F). Though summers can be humid, June manages to balance warm weather with a relatively lower average of 11 days of rainfall.
July weather
July is the peak of summer in Alton, IL, with the highest average temperatures reaching 31 °C (88 °F). It's a time to enjoy the sun, as well as to be cautious of heat and stay hydrated, especially on the 10 days of expected wet conditions.
August weather
August maintains the summer warmth in Alton, IL with an average high temperature of 30 °C (87 °F). The tail-end of summer can bring unexpected storms, reflected in the 10 days average of wet days, while the summer sun continues to beam down.
September weather
September in Alton, IL witnesses a gradual decline in temperatures to a comfortable average high of 27 °C (80 °F). The onset of fall brings fewer wet days 8 days, and a beautiful transformation of the foliage.
October weather
As October arrives in Alton, IL, autumn colors are in full display. The temperature cools to a pleasant average high of 20 °C (68 °F), and with roughly 9 days of precipitation, it's a delightful time to enjoy the changing seasons.
November weather
In November, the chill of late fall settles over Alton, IL, with temperatures averaging 13 °C (55 °F) during the day. Wet days increase slightly to 9 days, and shorter days mean less sunlight but create a cozy atmosphere for indoor gatherings.
December weather
December marks the onset of winter in Alton, IL, with temperatures dipping to an average high of 5 °C (42 °F). The holiday season may see an increase in wet weather, averaging 8 days, and a festive blanket of snow is always a possibility.
FAQs
How cold are the nights in Alton, IL during January?
Nights in Alton, IL, during January are quite cold. With an average minimum temperature of -6 °C (21 °F), it's essential to have warm blankets and a good heating system.
Does the weather begin to warm up in Alton, IL in February?
February's weather in Alton, IL shows a slight uptick in temperatures with daytime highs reaching an average of 6 °C (44 °F), suggesting the beginning of a gradual warm-up.
What can I expect in terms of rain during March in Alton, IL?
March in Alton can be quite wet, with over 10 days of rainy conditions, so it's wise to keep a raincoat or umbrella nearby.
How much does it rain in Alton, IL during April?
April brings a significant amount of rain to Alton, averaging at 97 mm (3.84 in). It's the perfect time to witness the revitalizing effect of spring rains on local flora.
How often does it rain in Alton, IL in May?
Rainfall is a common occurrence in May with an average of 12 days, ensuring that the spring growth is lush and landscapes are verdant.
What is the average temperature during the day in Alton, IL in June?
Daytime temperatures in Alton, IL in June average a warm 29 °C (84 °F), making it perfect for swimming, barbecues, and other summer activities.
How should I dress for the weather in Alton, IL in July?
Dress in light, airy fabrics to stay comfortable in the hot July weather of Alton, which can peak at around 31 °C (88 °F). Don't forget sunscreen and a hat to protect from strong sun rays.
Is August typically the hottest month in Alton, IL?
August is one of the hotter months in Alton, though not typically the absolute hottest, with daytime temperatures averaging 30 °C (87 °F).
What is the average number of rainy days in Alton, IL in September?
September experiences a decrease in rainy days with an average of 8 days, allowing for more predictable outdoor events and activities.
Does October in Alton, IL have many wet days?
October has its fair share of wet days, averaging around 9 days, so it's wise to keep a jacket or umbrella handy for sporadic showers.
What temperatures should I expect in Alton, IL in November?
Expect cooler temperatures in November, with daytime highs averaging around 13 °C (55 °F), and a sharper drop in temperatures at night.
What kind of winter weather can I expect in Alton, IL in December?
December in Alton, IL is characterized by colder temperatures and a good chance of snow or icy conditions, with an average of 8 days of precipitation.
We make the most from 40 years of historical weather data to predict the best weather conditions.
Deciding on where to go for a holiday is hard sometimes. Get inspired by the most popular destinations.
We aggregate data from combining multiple weather sources to ensure accuracy of the highest order.