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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Climate and monthly weather forecast
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 (-4.1°C) and 11.3°F (-11.5°C). January, recording an average high temperature of 24.6°F (-4.1°C) and a low temperature of 11.3°F (-11.5°C), is Alton's coldest month. 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 low of 14.4°F (-9.8°C) and an average high of 28.2°F (-2.1°C). The weather during February records an average high-temperature of a still freezing cold 28.2°F (-2.1°C), closely mirroring the preceding month. Weather in February »
Weather in March
The first month of the spring, March, is a chilly month in Alton, Iowa, with an average temperature fluctuating between 29.5°F (-1.4°C) and 44.2°F (6.8°C). As March sets, the average high-temperature displays a significant increase, moving up from a freezing cold 28.2°F (-2.1°C) in February to a frosty 44.2°F (6.8°C). Weather in March »
Weather in April
April is a mild spring month in Alton, Iowa, with an average temperature fluctuating between 40.1°F (4.5°C) and 56.8°F (13.8°C). Noticing a change, the average high-temperature during April moves from March's chilly 44.2°F (6.8°C) to a moderate 56.8°F (13.8°C). Weather in April »
Weather in May
The last month of the spring, May, is an agreeable month in Alton, Iowa, with an average temperature varying between 51.6°F (10.9°C) and 68.5°F (20.3°C). The start of May is characterized by an increase in the average high-temperature, transitioning from a moderate 56.8°F (13.8°C) in April to a pleasant 68.5°F (20.3°C). Weather in May »
Weather in June
The first month of the summer, June, is a moderately hot month in Alton, Iowa, with an average temperature varying between 61.7°F (16.5°C) and 78.1°F (25.6°C). June brings a rise in the average high-temperature, transitioning from May's pleasant 68.5°F (20.3°C) to a warm 78.1°F (25.6°C). Weather in June »
Weather in July
July, like June, in Alton, Iowa, is a moderately hot summer month, with an average temperature varying between 63.3°F (17.4°C) and 81.7°F (27.6°C). With its high average temperature of 81.7°F (27.6°C) and a low of 63.3°F (17.4°C), July is regarded as the warmest month. The heat index in July is calculated to be a tropical 87.8°F (31°C). Weather in July »
Weather in August
August, the last month of the summer in Alton, is also a moderately hot month, with temperature in the range of an average high of 80.2°F (26.8°C) and an average low of 60.4°F (15.8°C). As Alton transitions from July to August, the average high-temperatures adjust to a still moderately hot 80.2°F (26.8°C), nearly the same as the previous 81.7°F (27.6°C). Weather in August »
Weather in September
September, the first month of the autumn in Alton, is also a moderately hot month, with an average temperature varying between 54.5°F (12.5°C) and 74.3°F (23.5°C). September's arrival subtly correlates with a reduction in the average high-temperature, down from a moderately hot 80.2°F (26.8°C) in August to a still warm 74.3°F (23.5°C). Weather in September »
Weather in October
October, like September, is another mild autumn month in Alton, Iowa, with an average temperature ranging between max 58.1°F (14.5°C) and min 42.6°F (5.9°C). The shift into October is characterized by a noticeable reduction in the average high-temperature, decreasing from September's moderately hot 74.3°F (23.5°C) to a refreshing 58.1°F (14.5°C). Weather in October »
Weather in November
November, the last month of the autumn in Alton, is another chilly month, with temperature in the range of an average low of 30.6°F (-0.8°C) and an average high of 44.1°F (6.7°C). Alton's weather in November involves a decrease in the average high-temperature, moving down from October's refreshing 58.1°F (14.5°C) to a chilly 44.1°F (6.7°C). Weather in November »
Weather in December
The first month of the winter, December, is also a subzero cold month in Alton, Iowa, with temperature in the range of an average low of 17.4°F (-8.1°C) and an average high of 28.8°F (-1.8°C). The onset of December marks a clear decrease in the average high-temperature, dropping from a frosty 44.1°F (6.7°C) in November to a freezing cold 28.8°F (-1.8°C). Weather in December »
Updated: Aug 9, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months?
January tends to be the coldest month, with temperatures averaging a daily high of 24.6°F (-4.1°C) and a low of 11.3°F (-11.5°C).
What is the most humid month in Alton?
With an average relative humidity of 86%, January is the most humid month in Alton.
What is the driest month in Alton?
January is the month with the least rainfall. Rain falls for 3.8 days and accumulates 0.79" (20mm) of precipitation.
How many days does it rain in Alton?
In Alton, during the entire year, the rain falls for 124 days and collects up to 24.09" (612mm) of precipitation.
When does it snow?
January through May, October through December are months with snowfall.
How much does it snow?
In Alton, during the entire year, snow falls for 49.5 days and aggregates up to 18.39" (467mm) of snow.
What is the month with the least sunshine?
The month with the least sunshine is January, with an average of 3.9h of sunshine.
What is the month with the lowest UV index?
January and December, with an average maximum UV index of 1, are months with the lowest UV index.
What is the snowiest month in Alton?
The month with the most snowfall is February, when snow falls for 10 days and typically aggregates up to 4.61" (117mm) of snow.
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?
June is the month with the most rainfall. Rain falls for 18 days and accumulates 3.82" (97mm) of precipitation.
When it does not snow?
In Alton, snow does not fall in June through September.
When are the longest days?
June has the longest days of the year, with an average of 15h and 18min of daylight.
What is the month with the highest UV index?
The months with the highest UV index are June and July, with an average maximum UV index of 6.
What is the hottest time of year in Alton?
In Alton, July is the warmest month, with temperatures averaging a high of 81.7°F (27.6°C) and a low of 63.3°F (17.4°C).
What month has the most sunshine?
The month with the most sunshine is July, with an average of 10.4h of sunshine.
What is the least humid month?
With an average relative humidity of 67%, October is the least humid month.
What is the month with the shortest days?
The month with the shortest days is December, with an average of 9h and 6min of daylight.
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).
Average pressure
Alton, IA
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.15"Hg - Average pressure in March:
30.06"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.92"Hg - Average pressure in June:
29.86"Hg
- Average pressure in July:
29.94"Hg - Average pressure in August:
29.95"Hg - Average pressure in September:
29.99"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed
Alton, IA
- Average wind speed in January:
10.6mph - Average wind speed in February:
10.5mph - Average wind speed in March:
10.9mph - Average wind speed in April:
11.3mph - Average wind speed in May:
9.8mph - Average wind speed in June:
8.9mph
- Average wind speed in July:
7.8mph - Average wind speed in August:
8.1mph - Average wind speed in September:
9.3mph - Average wind speed in October:
10.3mph - Average wind speed in November:
10.4mph - Average wind speed in December:
10.2mph
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).
Average humidity
Alton, IA
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (67%).
Average rainfall
Alton, IA
- Average rainfall in January:
0.79" - Average rainfall in February:
0.91" - Average rainfall in March:
1.73" - Average rainfall in April:
2.76" - Average rainfall in May:
3.31" - Average rainfall in June:
3.82"
- Average rainfall in July:
1.93" - Average rainfall in August:
2.28" - Average rainfall in September:
2.01" - Average rainfall in October:
2.2" - Average rainfall in November:
0.94" - Average rainfall in December:
1.42"
The wettest month (with the highest rainfall) is June (3.82").
The driest month (with the least rainfall) is January (0.79").
Average rainfall days
Alton, IA
- Average rainfall days in January:
3.8 days - Average rainfall days in February:
2.8 days - Average rainfall days in March:
9.8 days - Average rainfall days in April:
14.3 days - Average rainfall days in May:
17.2 days - Average rainfall days in June:
18 days
- Average rainfall days in July:
12.8 days - Average rainfall days in August:
13.4 days - Average rainfall days in September:
11.3 days - Average rainfall days in October:
9.9 days - Average rainfall days in November:
6.2 days - Average rainfall days in December:
4.5 days
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).
Average snowfall
Alton, IA
- Average snowfall in January:
3.43" - Average snowfall in February:
4.61" - Average snowfall in March:
2.83" - Average snowfall in April:
1.77" - Average snowfall in May:
0.2" - Average snowfall in June:
0"
The month with the highest snowfall is February (4.61").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Alton, IA
- Average snowfall days in January:
12.1 days - Average snowfall days in February:
10 days - Average snowfall days in March:
7.7 days - Average snowfall days in April:
2.6 days - Average snowfall days in May:
0.2 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
1.6 days - Average snowfall days in November:
4.3 days - Average snowfall days in December:
11 days
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).
Average daylight / Average sunshine
Alton, IA
- Average daylight in January:
9h and 2min - Average daylight in February:
10h and 4min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 2min - Average daylight in May:
14h and 4min - Average daylight in June:
15h and 2min
- Average daylight in July:
15h and 0min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 4min - Average daylight in December:
9h and 1min
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).
- Average sunshine in January:
3h and 5min - Average sunshine in February:
4h and 5min - Average sunshine in March:
6h and 1min - Average sunshine in April:
7h and 5min - Average sunshine in May:
8h and 3min - Average sunshine in June:
9h and 4min
- Average sunshine in July:
10h and 2min - Average sunshine in August:
9h and 4min - Average sunshine in September:
8h and 5min - Average sunshine in October:
5h and 5min - Average sunshine in November:
5h and 4min - Average sunshine in December:
4h and 2min
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).
Average sunshine days
Alton, IA
- Average sunshine days in January:
16.8 days - Average sunshine days in February:
14.8 days - Average sunshine days in March:
14.3 days - Average sunshine days in April:
12.4 days - Average sunshine days in May:
11.8 days - Average sunshine days in June:
9.3 days
- Average sunshine days in July:
15.1 days - Average sunshine days in August:
14.3 days - Average sunshine days in September:
16.5 days - Average sunshine days in October:
18 days - Average sunshine days in November:
20.3 days - Average sunshine days in December:
17.4 days
The month with the most sunshine days is November (20.3 days).
The month with the least sunshine days is June (9.3 days).
Average UV index
Alton, IA
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover
Alton, IA
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is July (Cloud cover 28).
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).