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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
Weather in January
January, the same as December, is an icy winter month in South Jacksonville, Illinois, with an average temperature varying between 21°F (-6.1°C) and 33.4°F (0.8°C). January is the month when South Jacksonville experiences its coldest temperatures, averaging a high of 33.4°F (0.8°C) and a low of 21°F (-6.1°C). Weather in January »
Weather in February
February, the last month of the winter in South Jacksonville, is another cold month, with an average temperature varying between 38.3°F (3.5°C) and 24.6°F (-4.1°C). The advent of February signifies a minor shift to an average high-temperature of a still icy 38.3°F (3.5°C), aligning closely with January. Weather in February »
Weather in March
The first month of the spring, March, is a fresh month in South Jacksonville, Illinois, with an average temperature ranging between min 36.1°F (2.3°C) and max 51.4°F (10.8°C). South Jacksonville's March weather brings a rise in high-temperatures, moving from an icy 38.3°F (3.5°C) in February to a cool 51.4°F (10.8°C). Weather in March »
Weather in April
April is a refreshing spring month in South Jacksonville, Illinois, with an average temperature ranging between min 46.2°F (7.9°C) and max 63.3°F (17.4°C). South Jacksonville's transition into April is marked by a rise in the average high-temperature, advancing from a cool 51.4°F (10.8°C) in March to a refreshing 63.3°F (17.4°C). Weather in April »
Weather in May
May, the last month of the spring in South Jacksonville, is an agreeable month, with temperature in the range of an average low of 55.9°F (13.3°C) and an average high of 72.9°F (22.7°C). South Jacksonville's weather in May presents a rise in the average high-temperature, moving from an enjoyable 63.3°F (17.4°C) in April to an agreeable 72.9°F (22.7°C). Weather in May »
Weather in June
June, the first month of the summer in South Jacksonville, is a warm month, with temperature in the range of an average high of 81.5°F (27.5°C) and an average low of 64.6°F (18.1°C). A soft shift in the average high-temperature is noticeable in June, transitioning from a pleasant 72.9°F (22.7°C) in May to a moderately hot 81.5°F (27.5°C). Weather in June »
Weather in July
July, the same as June, is a moderately hot summer month in South Jacksonville, Illinois, with temperature in the range of an average high of 83.3°F (28.5°C) and an average low of 66.7°F (19.3°C). In South Jacksonville, the highest average temperatures are observed in July, with a high of 83.3°F (28.5°C) and a low of 66.7°F (19.3°C). In July, the heat index is estimated at a hot 93.2°F (34°C). Weather in July »
Weather in August
August, the last month of the summer in South Jacksonville, is also a moderately hot month, with an average temperature ranging between max 82.6°F (28.1°C) and min 64.8°F (18.2°C). As South Jacksonville welcomes August, the average high-temperature is noted at a still moderately hot 82.6°F (28.1°C), closely aligning with the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in South Jacksonville, Illinois, with an average temperature varying between 58.6°F (14.8°C) and 77.7°F (25.4°C). September's presence records an average high-temperature of a still warm 77.7°F (25.4°C), closely mirroring August's climate. Weather in September »
Weather in October
October, the same as September, is another refreshing autumn month in South Jacksonville, Illinois, with an average temperature ranging between min 47.5°F (8.6°C) and max 64°F (17.8°C). As September transitions to October, the average high-temperature falls from a moderately hot 77.7°F (25.4°C) to an enjoyable 64°F (17.8°C). Weather in October »
Weather in November
November, the last month of the autumn in South Jacksonville, is another cool month, with an average temperature fluctuating between 36°F (2.2°C) and 50.5°F (10.3°C). The decrease of average high-temperatures is mild in November, with a decline from a refreshing 64°F (17.8°C) in October to a cool 50.5°F (10.3°C). Weather in November »
Weather in December
December, the first month of the winter in South Jacksonville, is still a cold month, with temperature in the range of an average low of 27.7°F (-2.4°C) and an average high of 39°F (3.9°C). The onset of December brings a small change in high-temperatures, falling from a cool 50.5°F (10.3°C) in November to a wintry 39°F (3.9°C). Weather in December »
Updated: Jun 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?
The coldest month is January, with an average high-temperature of 33.4°F (0.8°C) and an average low-temperature of 21°F (-6.1°C).
How many days does it rain?
Throughout the year, there are 148.2 rainfall days, and 29.37" (746mm) of precipitation is accumulated.
When does it snow?
Months with snowfall are January through April, October through December.
What is the snowiest month?
January is the month with the most snowfall. Snow falls for 9.6 days and accumulates 3.58" (91mm) of snow.
How many days does it snow?
Throughout the year, there are 28.3 snowfall days, and 9.76" (248mm) of snow is accumulated.
What is the month with the least sunshine?
With an average of 4.3h of sunshine, January has the least sunshine of the year.
When is the lowest UV index?
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.
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.
When it does not snow?
May through September are months without snowfall.
What is the wettest month?
The month with the most rainfall is June, when the rain falls for 15.8 days and typically aggregates up to 3.58" (91mm) of precipitation.
When are the longest days?
With an average of 14h and 54min of daylight, June has the longest days of the year.
What month has the most sunshine?
June has the most sunshine of the year, with an average of 10.3h of sunshine.
What is the month with the highest UV index?
June through August, with an average maximum UV index of 6, are months with the highest UV index.
What is the warmest month?
July is the month when South Jacksonville experiences its warmest temperatures, averaging a high of 83.3°F (28.5°C) and a low of 66.7°F (19.3°C).
What is the most humid month?
With an average relative humidity of 83%, July is the most humid month.
What is the least humid month?
October is the least humid month, with an average relative humidity of 71%.
What is the driest month in South Jacksonville?
December is the month with the least rainfall. Rain falls for 8.1 days and accumulates 1.54" (39mm) of precipitation.
What is the month with the shortest days?
The month with the shortest days is December, with an average of 9h and 24min of daylight.
Average temperature
South Jacksonville, IL
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (33.4°F).
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (21°F).
Average pressure
South Jacksonville, IL
- Average pressure in January:
30.15"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.07"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
South Jacksonville, IL
- Average wind speed in January:
10.1mph - Average wind speed in February:
10mph - Average wind speed in March:
9.9mph - Average wind speed in April:
10mph - Average wind speed in May:
8.2mph - Average wind speed in June:
7.1mph
- Average wind speed in July:
6.1mph - Average wind speed in August:
6.2mph - Average wind speed in September:
7mph - Average wind speed in October:
8.8mph - Average wind speed in November:
9.6mph - Average wind speed in December:
9.6mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is July (6.1mph).
Average humidity
South Jacksonville, IL
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall
South Jacksonville, IL
- Average rainfall in January:
1.69" - Average rainfall in February:
1.61" - Average rainfall in March:
2.28" - Average rainfall in April:
3.39" - Average rainfall in May:
3.46" - Average rainfall in June:
3.58"
- Average rainfall in July:
2.28" - Average rainfall in August:
2.4" - Average rainfall in September:
2.64" - Average rainfall in October:
2.72" - Average rainfall in November:
1.77" - Average rainfall in December:
1.54"
The wettest month (with the highest rainfall) is June (3.58").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days
South Jacksonville, IL
- Average rainfall days in January:
7.1 days - Average rainfall days in February:
7.1 days - Average rainfall days in March:
13.5 days - Average rainfall days in April:
15.8 days - Average rainfall days in May:
18 days - Average rainfall days in June:
15.8 days
- Average rainfall days in July:
15.8 days - Average rainfall days in August:
13.5 days - Average rainfall days in September:
11.7 days - Average rainfall days in October:
11.8 days - Average rainfall days in November:
10 days - Average rainfall days in December:
8.1 days
The month with the highest number of rainy days is May (18 days).
The months with the least rainy days are January and February (7.1 days).
Average snowfall
South Jacksonville, IL
The month with the highest snowfall is January (3.58").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
South Jacksonville, IL
- Average snowfall days in January:
9.6 days - Average snowfall days in February:
7.2 days - Average snowfall days in March:
3.3 days - Average snowfall days in April:
0.8 days - Average snowfall days in May:
0 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:
0.2 days - Average snowfall days in November:
2.2 days - Average snowfall days in December:
5 days
The month with the highest number of snowfall days is January (9.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
South Jacksonville, IL
- Average daylight in January:
9h and 4min - 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 2min - Average daylight in June:
14h and 5min
- Average daylight in July:
14h and 4min - Average daylight in August:
13h and 4min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 1min - Average daylight in November:
10h and 0min - Average daylight in December:
9h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in January:
4h and 2min - Average sunshine in February:
4h and 4min - Average sunshine in March:
6h and 4min - Average sunshine in April:
8h and 2min - Average sunshine in May:
9h and 2min - Average sunshine in June:
10h and 2min
- Average sunshine in July:
10h and 1min - Average sunshine in August:
10h and 0min - Average sunshine in September:
9h and 2min - Average sunshine in October:
5h and 5min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days
South Jacksonville, IL
- Average sunshine days in January:
15.9 days - Average sunshine days in February:
14.8 days - Average sunshine days in March:
14.1 days - Average sunshine days in April:
11.9 days - Average sunshine days in May:
11 days - Average sunshine days in June:
10.5 days
- Average sunshine days in July:
12.3 days - Average sunshine days in August:
15 days - Average sunshine days in September:
15.7 days - Average sunshine days in October:
17.3 days - Average sunshine days in November:
18.1 days - Average sunshine days in December:
18.5 days
The month with the most sunshine days is December (18.5 days).
The month with the least sunshine days is June (10.5 days).
Average UV index
South Jacksonville, IL
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
South Jacksonville, IL
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility
South Jacksonville, IL
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
South Jacksonville, Illinois, USA
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