Climate and monthly weather forecastForreston, IL
Climate and monthly weather forecast
Weather in January
January, like December, is another subzero cold winter month in Forreston, Illinois, with an average temperature varying between 13.5°F (-10.3°C) and 26.1°F (-3.3°C). January is the coldest month, with an average high-temperature of 26.1°F (-3.3°C) and an average low-temperature of 13.5°F (-10.3°C). Weather in January »Weather in February
February, the last month of the winter in Forreston, is another freezing cold month, with an average temperature ranging between max 30°F (-1.1°C) and min 17.1°F (-8.3°C). As Forreston, Illinois, welcomes February, the average high-temperature records at a still freezing cold 30°F (-1.1°C), marking an insignificant deviation from the prior month. Weather in February »Weather in March
March, the first month of the spring in Forreston, is a chilly month, with an average temperature varying between 29.7°F (-1.3°C) and 44.2°F (6.8°C). Forreston sees an increase in the average high-temperature with the arrival of March, moving from February's subzero cold 30°F (-1.1°C) to a chilly 44.2°F (6.8°C). Weather in March »Weather in April
April in Forreston, Illinois, is a moderate spring month, with an average temperature fluctuating between 56.5°F (13.6°C) and 39.7°F (4.3°C). April comes with an increase, with the average high-temperature moving from a chilly 44.2°F (6.8°C) in March to a mild 56.5°F (13.6°C). Weather in April »Weather in May
May, the last month of the spring in Forreston, is a pleasant month, with an average temperature ranging between min 51.4°F (10.8°C) and max 68.5°F (20.3°C). In Forreston, the average high-temperature in May increases from a refreshing 56.5°F (13.6°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 Forreston, Illinois, with temperature in the range of an average low of 60.1°F (15.6°C) and an average high of 77.2°F (25.1°C). As May transitions into June, Forreston notices a gentle rise in the average high-temperature, transitioning from a pleasant 68.5°F (20.3°C) to a warm 77.2°F (25.1°C). Weather in June »Weather in July
July, the same as June, is another warm summer month in Forreston, Illinois, with temperature in the range of an average high of 79.7°F (26.5°C) and an average low of 63.5°F (17.5°C). July brings the highest temperatures, with an average high of 79.7°F (26.5°C) and an average low of 63.5°F (17.5°C). Weather in July »Weather in August
August, the last month of the summer in Forreston, is also a moderately hot month, with an average temperature ranging between max 78.4°F (25.8°C) and min 61°F (16.1°C). Forreston, Illinois, records a slight change with August's average high-temperatures adjusting to a still warm 78.4°F (25.8°C) from July's 79.7°F (26.5°C). Weather in August »Weather in September
September, the first month of the autumn in Forreston, is still a pleasant month, with an average temperature ranging between max 72.9°F (22.7°C) and min 54.5°F (12.5°C). A modest decline in the average high-temperature is seen during September, decreasing from a moderately hot 78.4°F (25.8°C) in August to a pleasant 72.9°F (22.7°C). Weather in September »Weather in October
October, like September, is a moderate autumn month in Forreston, Illinois, with temperature in the range of an average low of 43.7°F (6.5°C) and an average high of 59.4°F (15.2°C). The decrease of average high-temperatures is mild in October, with a decline from a pleasant 72.9°F (22.7°C) in September to a refreshing 59.4°F (15.2°C). Weather in October »Weather in November
November, the last month of the autumn in Forreston, is also a frosty month, with an average temperature varying between 31.5°F (-0.3°C) and 44.6°F (7°C). Forreston sees a considerable decrease in average high-temperatures during November, falling from a refreshing 59.4°F (15.2°C) in October to a chilly 44.6°F (7°C). Weather in November »Weather in December
The first month of the winter, December, is still a cold month in Forreston, Illinois, with an average temperature ranging between max 32.4°F (0.2°C) and min 22.3°F (-5.4°C). Forreston's December weather shows a moderate shift in high-temperatures, falling from November's chilly 44.6°F (7°C) to an icy 32.4°F (0.2°C). Weather in December »Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Forreston, IL
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (26.1°F).
The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure
Forreston, IL
- Average pressure in January:
30.12"Hg - Average pressure in February:
30.11"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Forreston, IL
- Average wind speed in January:
9.9mph - Average wind speed in February:
10mph - Average wind speed in March:
9.8mph - Average wind speed in April:
10.3mph - Average wind speed in May:
8.8mph - Average wind speed in June:
7.6mph
- Average wind speed in July:
6.6mph - Average wind speed in August:
6.5mph - Average wind speed in September:
7.5mph - Average wind speed in October:
9.1mph - Average wind speed in November:
9.8mph - Average wind speed in December:
9.4mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity
Forreston, IL
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April and October (75%).
Average rainfall
Forreston, IL
- Average rainfall in January:
1.14" - Average rainfall in February:
1.06" - Average rainfall in March:
1.38" - Average rainfall in April:
2.48" - Average rainfall in May:
3.19" - Average rainfall in June:
3.39"
- Average rainfall in July:
2.44" - Average rainfall in August:
2.01" - Average rainfall in September:
1.81" - Average rainfall in October:
2.13" - Average rainfall in November:
1.34" - Average rainfall in December:
1.06"
The wettest month (with the highest rainfall) is June (3.39").
The driest months (with the least rainfall) are February and December (1.06").
Average rainfall days
Forreston, IL
- Average rainfall days in January:
5.1 days - Average rainfall days in February:
5 days - Average rainfall days in March:
11.4 days - Average rainfall days in April:
15.3 days - Average rainfall days in May:
18.3 days - Average rainfall days in June:
17.7 days
- Average rainfall days in July:
17.3 days - Average rainfall days in August:
15.3 days - Average rainfall days in September:
11.7 days - Average rainfall days in October:
12.3 days - Average rainfall days in November:
8.7 days - Average rainfall days in December:
7.5 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (5 days).
Average snowfall
Forreston, IL
The month with the highest snowfall is January (3.54").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Forreston, IL
- Average snowfall days in January:
12.4 days - Average snowfall days in February:
10.9 days - Average snowfall days in March:
6.3 days - Average snowfall days in April:
2 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:
0.5 days - Average snowfall days in November:
3.5 days - Average snowfall days in December:
9.9 days
The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Forreston, IL
- Average daylight in January:
9h and 30min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 36min - Average daylight in June:
15h and 12min
- Average daylight in July:
14h and 54min - Average daylight in August:
13h and 48min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 6min - Average daylight in November:
9h and 48min - Average daylight in December:
9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
3h and 36min - Average sunshine in February:
3h and 42min - Average sunshine in March:
6h and 6min - Average sunshine in April:
7h and 30min - Average sunshine in May:
8h and 24min - Average sunshine in June:
9h and 30min
- Average sunshine in July:
9h and 42min - Average sunshine in August:
9h and 30min - Average sunshine in September:
8h and 42min - Average sunshine in October:
5h and 18min - Average sunshine in November:
5h and 0min - Average sunshine in December:
4h and 0min
The month with the most sunshine is July (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days
Forreston, IL
- Average sunshine days in January:
14.9 days - Average sunshine days in February:
12.8 days - Average sunshine days in March:
14.4 days - Average sunshine days in April:
11.3 days - Average sunshine days in May:
10.5 days - Average sunshine days in June:
9.7 days
- Average sunshine days in July:
10.4 days - Average sunshine days in August:
12.9 days - Average sunshine days in September:
16.4 days - Average sunshine days in October:
16.2 days - Average sunshine days in November:
17.2 days - Average sunshine days in December:
16.3 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (9.7 days).
Average UV index
Forreston, IL
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover
Forreston, IL
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is September (Cloud cover 33).
Average visibility
Forreston, IL
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).





