Climate and monthly weather forecast
Alton, IA

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Weather in January

January, the same as December, in Alton, Iowa, is a freezing cold winter month, with an average temperature fluctuating between 24.6°F and 11.3°F. Alton's coldest temperatures are experienced in January, with average high temperatures of 24.6°F and lows of 11.3°F. Weather in January »

Weather in February

February, the last month of the winter in Alton, is also a subzero cold month, with temperature in the range of an average high of 28.2°F and an average low of 14.4°F. The start of February sees the average high-temperature at a still freezing cold 28.2°F, showing little difference from January's 24.6°F. Weather in February »

Weather in March

The first month of the spring, March, is a frosty month in Alton, Iowa, with temperature in the range of an average high of 44.2°F and an average low of 29.5°F. As March begins, there is a noticeable increase in the average high-temperature, soaring from a subzero cold 28.2°F in February to a chilly 44.2°F. Weather in March »

Weather in April

April in Alton, Iowa, is a mild spring month, with an average temperature ranging between max 56.8°F and min 40.1°F. April's onset brings a rise in the average high-temperature, moving from a frosty 44.2°F in March to a mild 56.8°F. Weather in April »

Weather in May

The last month of the spring, May, is a pleasant month in Alton, Iowa, with temperature in the range of an average high of 68.5°F and an average low of 51.6°F. The shift into May brings an increase in the average high-temperature, moving from a mild 56.8°F in April to a pleasant 68.5°F. Weather in May »

Weather in June

June, the first month of the summer in Alton, is a moderately hot month, with an average temperature varying between 78.1°F and 61.7°F. The arrival of June brings a temperature shift, with the average high-temperature escalating from a pleasant 68.5°F in May to a warm 78.1°F. Weather in June »

Weather in July

July, the same as June, is another warm summer month in Alton, Iowa, with an average temperature fluctuating between 81.7°F and 63.3°F. Temperature readings reach their annual highs in July, averaging 81.7°F and a minimum average of 63.3°F. The heat index for July is estimated at a hot 87.8°F. Weather in July »

Weather in August

The last month of the summer, August, is also a moderately hot month in Alton, Iowa, with an average temperature ranging between max 80.2°F and min 60.4°F. In August, Alton experiences a barely noticeable shift in meteorological conditions, with average high-temperatures moving from 81.7°F in July to a still warm 80.2°F. 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 low of 54.5°F and an average high of 74.3°F. Alton's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's warm 80.2°F to a still moderately hot 74.3°F. Weather in September »

Weather in October

October, like September, is a moderate autumn month in Alton, Iowa, with an average temperature ranging between min 42.6°F and max 58.1°F. October's arrival is marked by a significant decrease in the average high-temperature, moving from a moderately hot 74.3°F in September to a mild 58.1°F. Weather in October »

Weather in November

The last month of the autumn, November, is another chilly month in Alton, Iowa, with an average temperature varying between 44.1°F and 30.6°F. As November begins, there is a decrease in the average high-temperature, falling from a moderate 58.1°F in October to a frosty 44.1°F. Weather in November »

Weather in December

December, the first month of the winter in Alton, is also a subzero cold month, with temperature in the range of an average low of 17.4°F and an average high of 28.8°F. The onset of December witnesses a clear shift in the average high-temperature, dropping from a chilly 44.1°F in November to a freezing cold 28.8°F. Weather in December »
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FAQ

What is the coldest time of year in Alton?

January, with an average high of 24.6°F and a low of 11.3°F, signifies the coldest month of the year.

What is the most humid month in Alton?

The most humid month in Alton, Iowa, is January, with an average relative humidity of 86%.

What is the driest month in Alton?

The month with the least rainfall is January, when the rain falls for 3.8 days and typically collects 0.79" of precipitation.

How many days does it rain in Alton?

Throughout the year, there are 124 rainfall days, and 24.09" of precipitation is accumulated.

When does it snow in Alton?

January through May, October through December are months with snowfall in Alton.

How much does it snow in Alton?

In Alton, Iowa, during the entire year, snow falls for 49.5 days and aggregates up to 18.39" of snow.

What is the month with the least sunshine in Alton?

With an average of 3.9h of sunshine, January has the least sunshine of the year.

When is the lowest UV index in Alton?

The months with the lowest UV index in Alton, Iowa, are January and December, with an average maximum UV index of 1.

When does it snow the most in Alton?

The month with the most snowfall in Alton, Iowa, is February, when snow falls for 10 days and typically aggregates up to 4.61" of snow.

When is Daylight Saving Time (DST) in Alton?

On Sunday, March 12. 2023, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 5. 2023, at 2:00 am, and the time zone reverts from CDT to CST.

What is the rainiest month in Alton?

June is the month with the most rainfall. Rain falls for 18 days and accumulates 3.82" of precipitation.

When it does not snow in Alton?

In Alton, Iowa, snow does not fall in June through September.

When are the longest days in Alton?

The month with the longest days in Alton, Iowa, is June, with an average of 15h and 18min of daylight.

When is the highest UV index in Alton?

The months with the highest UV index in Alton, Iowa, are June and July, with an average maximum UV index of 6.

What are the warmest months in Alton?

Alton's temperatures tend to reach their peak averages in July, with a high of 81.7°F and a low of 63.3°F.

What month has the most sunshine in Alton?

July has the most sunshine of the year in Alton, with an average of 10.4h of sunshine.

What is the least humid month in Alton?

The least humid month is October, with an average relative humidity of 67%.

What is the month with the shortest days in Alton?

December has the shortest days of the year in Alton, with an average of 9h and 6min of daylight.

Average temperature
Alton, IA

Average temperature - Alton, IA

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (24.6°F).

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (11.3°F).

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Average pressure
Alton, IA

Average pressure - Alton, IA

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).

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Average wind speed
Alton, IA

Average wind speed - Alton, IA

The windiest month (with the highest average wind speed) is April (11.3mph).
The calmest month (with the lowest average wind speed) is July (7.8mph).

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Average rainfall
Alton, IA

Average rainfall - Alton, IA

The wettest month (with the highest rainfall) is June (3.82").
The driest month (with the least rainfall) is January (0.79").

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Average rainfall days
Alton, IA

Average rainfall days - Alton, IA

The month with the highest number of rainy days is June (18 days).
The month with the least rainy days is February (2.8 days).

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Average snowfall
Alton, IA

Average snowfall - Alton, IA

The month with the highest snowfall is February (4.61").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days
Alton, IA

Average snowfall days - Alton, IA

The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight / Average sunshine
Alton, IA

Average daylight / Average sunshine - Alton, IA

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

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Average sunshine days
Alton, IA

Average sunshine days - Alton, IA

The month with the most sunshine days is November (20.3 days).
The month with the least sunshine days is June (9.3 days).

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Average visibility
Alton, IA

Average visibility - Alton, IA

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

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Alton, Iowa, USA

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