Climate and monthly weather forecastJacksonville, IL
Climate and monthly weather forecast
Weather in January
January, like December, in Jacksonville, Illinois, is an icy winter month, with an average temperature fluctuating between 21°F (-6.1°C) and 33.4°F (0.8°C). Jacksonville's coldest weather arrives in January, when temperatures average a high of 33.4°F (0.8°C) and a low of 21°F (-6.1°C). Weather in January »Weather in February
The last month of the winter, February, is also a wintry month in Jacksonville, Illinois, with an average temperature fluctuating between 38.3°F (3.5°C) and 24.6°F (-4.1°C). The dawn of February sees an average high-temperature of a still wintry 38.3°F (3.5°C), subtly contrasting with January's 33.4°F (0.8°C). Weather in February »Weather in March
March, the first month of the spring in Jacksonville, is a fresh month, with an average temperature fluctuating between 51.4°F (10.8°C) and 36.1°F (2.3°C). Jacksonville, Illinois, sees an increase in the average high-temperature with the arrival of March, moving from February's icy 38.3°F (3.5°C) to a cool 51.4°F (10.8°C). Weather in March »Weather in April
April in Jacksonville, Illinois, is a comfortable spring month, with temperature in the range of an average high of 63.3°F (17.4°C) and an average low of 46.2°F (7.9°C). The beginning of April marks a shift in the average high-temperature, moving from March's cool 51.4°F (10.8°C) to a refreshing 63.3°F (17.4°C). Weather in April »Weather in May
The last month of the spring, May, is a pleasant month in Jacksonville, Illinois, with an average temperature fluctuating between 55.9°F (13.3°C) and 72.9°F (22.7°C). May brings a temperature increase, with average high-temperatures moving from April's refreshing 63.3°F (17.4°C) to an agreeable 72.9°F (22.7°C). Weather in May »Weather in June
The first month of the summer, June, is a warm month in Jacksonville, Illinois, with an average temperature ranging between max 81.5°F (27.5°C) and min 64.6°F (18.1°C). As June begins, there's a slight increase in the average high-temperature, moving from an agreeable 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 another warm summer month in Jacksonville, Illinois, with an average temperature fluctuating between 83.3°F (28.5°C) and 66.7°F (19.3°C). In Jacksonville, the month of July registers the highest temperatures, averaging 83.3°F (28.5°C) at the peak and 66.7°F (19.3°C) at the lowest. Throughout 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 Jacksonville, is another warm month, with temperature in the range of an average high of 82.6°F (28.1°C) and an average low of 64.8°F (18.2°C). In August, Jacksonville's weather conditions record an average high-temperature of a still warm 82.6°F (28.1°C), demonstrating little divergence from the preceding month. Weather in August »Weather in September
The first month of the autumn, September, is still a warm month in Jacksonville, Illinois, with temperature in the range of an average high of 77.7°F (25.4°C) and an average low of 58.6°F (14.8°C). Jacksonville's weather in September, with an average high-temperature of a still warm 77.7°F (25.4°C), subtly shifts from August's 82.6°F (28.1°C). Weather in September »Weather in October
October, the same as September, is another comfortable autumn month in Jacksonville, Illinois, with an average temperature fluctuating between 47.5°F (8.6°C) and 64°F (17.8°C). October is characterized by a reduction in the average high-temperature, from a moderately hot 77.7°F (25.4°C) in September to a comfortable 64°F (17.8°C). Weather in October »Weather in November
November, the last month of the autumn in Jacksonville, is another cool month, with temperature in the range of an average low of 36°F (2.2°C) and an average high of 50.5°F (10.3°C). The decrease of average high-temperatures is mild in November, with a decline from a comfortable 64°F (17.8°C) in October to a fresh 50.5°F (10.3°C). Weather in November »Weather in December
The first month of the winter, December, is also a wintry month in Jacksonville, Illinois, with an average temperature varying between 39°F (3.9°C) and 27.7°F (-2.4°C). The commencement of December involves a temperature shift, with the average high-temperature dropping from a fresh 50.5°F (10.3°C) in November to a wintry 39°F (3.9°C). Weather in December »Updated: Jun 26, 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
The coldest period is January, when temperatures fluctuate between an average high of 33.4°F (0.8°C) and a low of 21°F (-6.1°C).
Throughout the year, there are 148.2 rainfall days, and 29.37" (746mm) of precipitation is accumulated.
Months with snowfall are January through April, October through December.
The month with the most snowfall is January, when snow falls for 9.6 days and typically aggregates up to 3.58" (91mm) of snow.
Throughout the year, there are 28.3 snowfall days, and 9.76" (248mm) of snow is accumulated.
The month with the least sunshine is January, with an average of 4.3h of sunshine.
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Jacksonville, 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.
In Jacksonville, snow does not fall in May through September.
June is the month with the most rainfall. Rain falls for 15.8 days and accumulates 3.58" (91mm) of precipitation.
The month with the longest days is June, with an average of 14h and 54min of daylight.
June has the most sunshine of the year, with an average of 10.3h of sunshine.
June through August, with an average maximum UV index of 6, are months with the highest UV index.
With average high and low temperatures of 83.3°F (28.5°C) and 66.7°F (19.3°C) respectively, July is Jacksonville's warmest month.
The most humid month is July, with an average relative humidity of 83%.
October is the least humid month, with an average relative humidity of 71%.
December is the month with the least rainfall. Rain falls for 8.1 days and accumulates 1.54" (39mm) of precipitation.
December has the shortest days of the year, with an average of 9h and 24min of daylight.
Average temperature
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
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
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
Jacksonville, IL
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall
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
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
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
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
Jacksonville, IL
- Average daylight in January:
9h and 42min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 24min - Average daylight in June:
14h and 54min
- Average daylight in July:
14h and 42min - Average daylight in August:
13h and 42min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 6min - Average daylight in November:
10h and 0min - Average daylight in December:
9h and 24min
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 18min - Average sunshine in February:
4h and 36min - Average sunshine in March:
6h and 36min - Average sunshine in April:
8h and 24min - Average sunshine in May:
9h and 18min - Average sunshine in June:
10h and 18min
- Average sunshine in July:
10h and 12min - Average sunshine in August:
10h and 0min - Average sunshine in September:
9h and 24min - Average sunshine in October:
5h and 54min - Average sunshine in November:
5h and 24min - Average sunshine in December:
4h and 48min
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
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
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
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
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).
