Climate and monthly weather forecast
Alton, MO

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Weather in January

January, like December, is a frosty winter month in Alton, Missouri, with temperature in the range of an average low of 28.4°F (-2°C) and an average high of 43.3°F (6.3°C). January is the coldest month, with the temperature often reaching an average high of 43.3°F (6.3°C) and an average low of 28.4°F (-2°C). Weather in January »

Weather in February

The last month of the winter, February, is also a frosty month in Alton, Missouri, with temperature in the range of an average high of 47.5°F (8.6°C) and an average low of 31.8°F (-0.1°C). February denotes a minimal variation in the average high-temperature to a still chilly 47.5°F (8.6°C) from January's 43.3°F (6.3°C). Weather in February »

Weather in March

March, the first month of the spring in Alton, is a mild month, with temperature in the range of an average high of 57.7°F (14.3°C) and an average low of 40.1°F (4.5°C). March's arrival brings a temperature shift, moving from a chilly 47.5°F (8.6°C) in February to a refreshing 57.7°F (14.3°C). Weather in March »

Weather in April

April is a refreshing spring month in Alton, Missouri, with temperature in the range of an average high of 67.8°F (19.9°C) and an average low of 48.9°F (9.4°C). An escalation in the average high-temperature is seen with the onset of April, moving from a refreshing 57.7°F (14.3°C) in March to a comfortable 67.8°F (19.9°C). Weather in April »

Weather in May

May, the last month of the spring in Alton, is a warm month, with an average temperature fluctuating between 57.6°F (14.2°C) and 77.2°F (25.1°C). With the onset of May, Alton's average high-temperature experiences a rise, moving from April's refreshing 67.8°F (19.9°C) to a moderately hot 77.2°F (25.1°C). Weather in May »

Weather in June

June, the first month of the summer in Alton, is a hot month, with temperature in the range of an average high of 86.9°F (30.5°C) and an average low of 66°F (18.9°C). In Alton, the average high-temperature in June increases from a warm 77.2°F (25.1°C) in May to a tropical 86.9°F (30.5°C). Weather in June »

Weather in July

July, the same as June, in Alton, Missouri, is another hot summer month, with temperature in the range of an average low of 68.5°F (20.3°C) and an average high of 89.4°F (31.9°C). July, on average, is the warmest month, registering a high temperature of 89.4°F (31.9°C) and a low of 68.5°F (20.3°C). July's mean heat index is computed to be a blistering 107.6°F (42°C). Weather in July »

Weather in August

August, the last month of the summer in Alton, is another tropical month, with an average temperature ranging between min 67.5°F (19.7°C) and max 88.3°F (31.3°C). August's arrival brings an average high-temperature of a still tropical 88.3°F (31.3°C), slightly deviating from July's 89.4°F (31.9°C). Weather in August »

Weather in September

September, the first month of the autumn in Alton, is also a moderately hot month, with temperature in the range of an average high of 81.9°F (27.7°C) and an average low of 60.8°F (16°C). September witnesses a gentle descent in average high-temperature, descending from August's tropical 88.3°F (31.3°C) to a moderately hot 81.9°F (27.7°C). Weather in September »

Weather in October

October, the same as September, in Alton, Missouri, is another pleasant autumn month, with an average temperature ranging between max 69.1°F (20.6°C) and min 49.8°F (9.9°C). The beginning of October marks a decrease in the average high-temperature, transitioning from a warm 81.9°F (27.7°C) in September to an agreeable 69.1°F (20.6°C). Weather in October »

Weather in November

The last month of the autumn, November, is another refreshing month in Alton, Missouri, with an average temperature ranging between min 39.7°F (4.3°C) and max 56.1°F (13.4°C). With the beginning of November, the average high-temperature shows a decrease, transitioning from an agreeable 69.1°F (20.6°C) in October to a mild 56.1°F (13.4°C). Weather in November »

Weather in December

The first month of the winter, December, is also a frosty month in Alton, Missouri, with an average temperature varying between 46.8°F (8.2°C) and 32.5°F (0.3°C). The start of December signals a decrease in the average high-temperature, transitioning from a moderate 56.1°F (13.4°C) in November to a frosty 46.8°F (8.2°C). Weather in December »

Frequently asked questions

What part of the year is the coldest?

January, known for its average high temperature of 43.3°F (6.3°C) and an average low temperature of 28.4°F (-2°C), is the coldest month.

How much does it rain?

Throughout the year, there are 148 rainfall days, and 35.39" (899mm) of precipitation is accumulated.

When does it snow?

January through April, November and December are months with snowfall.

How many days does it snow?

In Alton, during the entire year, snow falls for 8.9 days and aggregates up to 4.57" (116mm) of snow.

What are the months with the lowest UV index?

The months with the lowest UV index are January and December, with an average maximum UV index of 2.

What is the snowiest month?

The month with the most snowfall is February, when snow falls for 2.8 days and typically aggregates up to 1.26" (32mm) of snow.

What is the month with the least sunshine?

February has the least sunshine of the year, with an average of 4.8h of sunshine.

What is the most humid month?

March and May, with an average relative humidity of 79%, are most humid months.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.

What is the wettest month?

The month with the most rainfall is May, when the rain falls for 16.5 days and typically aggregates up to 4.25" (108mm) of precipitation.

When it does not snow?

May through October are months without snowfall.

When are the longest days?

The month with the longest days is June, with an average of 14h and 36min of daylight.

What month has the most sunshine?

June has the most sunshine of the year, with an average of 10.4h of sunshine.

What is the month with the highest UV index?

The month with the highest UV index in Alton is June, with an average maximum UV index of 7.

What is the hottest time of year?

The warmest month in Alton is July, with an average high-temperature of 89.4°F (31.9°C) and an average low-temperature of 68.5°F (20.3°C).

What is the driest month?

The month with the least rainfall is September, when the rain falls for 12 days and typically collects 1.57" (40mm) of precipitation.

What is the least humid month?

October is the least humid month, with an average relative humidity of 72%.

What is the month with the shortest days?

With an average of 9h and 42min of daylight, December has the shortest days of the year.

Average temperature
Alton, MO

Average temperature - Alton, MO

The warmest month (with the highest average high temperature) is July (89.4°F).
The month with the lowest average high temperature is January (43.3°F).

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (28.4°F).

Average pressure
Alton, MO

Average pressure - Alton, MO

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed
Alton, MO

Average wind speed - Alton, MO

The windiest months (with the highest average wind speed) are January, February, March and April (8.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).

Average humidity
Alton, MO

Average humidity - Alton, MO

The months with the highest relative humidity are March and May (79%).
The month with the lowest relative humidity is October (72%).

Average rainfall
Alton, MO

Average rainfall - Alton, MO

The wettest month (with the highest rainfall) is May (4.25").
The driest month (with the least rainfall) is September (1.57").

Average rainfall days
Alton, MO

Average rainfall days - Alton, MO

The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (8.6 days).

Average snowfall
Alton, MO

Average snowfall - Alton, MO

The month with the highest snowfall is February (1.26").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days
Alton, MO

Average snowfall days - Alton, MO

The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight / Average sunshine
Alton, MO

Average daylight / Average sunshine - Alton, MO

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days
Alton, MO

Average sunshine days - Alton, MO

The month with the most sunshine days is December (19.6 days).
The month with the least sunshine days is May (12.3 days).

Average visibility
Alton, MO

Average visibility - Alton, MO

The months with the highest visibility are January, February, March, April, June, August, September, October, November and December (6mi).
The months with the lowest visibility are May and July (5mi).

Alton, Missouri, USA

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