Climate and monthly weather forecastSumner, IL
Climate and monthly weather forecast
Weather in January
January, like December, in Sumner, Illinois, is a wintry winter month, with an average temperature varying between 36.7°F (2.6°C) and 24.4°F (-4.2°C). Sumner, Illinois, reaches its lowest average temperatures in January, measuring 36.7°F (2.6°C) at the peak and 24.4°F (-4.2°C) at the lowest. Weather in January »Weather in February
The last month of the winter, February, is also a wintry month in Sumner, Illinois, with an average temperature fluctuating between 41.9°F (5.5°C) and 28.2°F (-2.1°C). An average high-temperature of a still icy 41.9°F (5.5°C) marks February, exhibiting a close resemblance to the conditions in January. Weather in February »Weather in March
March, the first month of the spring in Sumner, is a fresh month, with an average temperature varying between 37.8°F (3.2°C) and 53.1°F (11.7°C). March signals a shift in the average high-temperature, moving from February's cold 41.9°F (5.5°C) to a cool 53.1°F (11.7°C). Weather in March »Weather in April
April in Sumner, Illinois, is a refreshing spring month, with an average temperature varying between 64.4°F (18°C) and 47.7°F (8.7°C). In Sumner, the average high-temperature in April increases from a fresh 53.1°F (11.7°C) in March to an enjoyable 64.4°F (18°C). Weather in April »Weather in May
May, the last month of the spring in Sumner, is a moderately hot month, with an average temperature ranging between max 73.9°F (23.3°C) and min 57.7°F (14.3°C). Sumner sees an increase in the average high-temperature with the arrival of May, moving from April's enjoyable 64.4°F (18°C) to a warm 73.9°F (23.3°C). Weather in May »Weather in June
The first month of the summer, June, is still a warm month in Sumner, Illinois, with temperature in the range of an average high of 82°F (27.8°C) and an average low of 65.5°F (18.6°C). The start of June brings a subtle shift in the average high-temperature, edging up from May's 73.9°F (23.3°C) to a still moderately hot 82°F (27.8°C). Weather in June »Weather in July
July, the same as June, is another warm summer month in Sumner, Illinois, with an average temperature fluctuating between 84°F (28.9°C) and 67.3°F (19.6°C). In Sumner, July is the warmest month, with temperatures averaging a high of 84°F (28.9°C) and a low of 67.3°F (19.6°C). July's heat index is calculated to be a very hot 95°F (35°C). Weather in July »Weather in August
The last month of the summer, August, is another warm month in Sumner, Illinois, with an average temperature varying between 82.9°F (28.3°C) and 65.7°F (18.7°C). In Sumner, August's average high-temperature stands at a still warm 82.9°F (28.3°C), closely related to the preceding month. Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in Sumner, Illinois, with an average temperature fluctuating between 78.3°F (25.7°C) and 60.1°F (15.6°C). September registers an average high-temperature of a still warm 78.3°F (25.7°C), slightly varied from August's 82.9°F (28.3°C). Weather in September »Weather in October
October, like September, in Sumner, Illinois, is another enjoyable autumn month, with an average temperature ranging between min 49.3°F (9.6°C) and max 66°F (18.9°C). Welcoming October, Sumner observes a shift in the average high-temperature, falling from September's moderately hot 78.3°F (25.7°C) to an enjoyable 66°F (18.9°C). Weather in October »Weather in November
The last month of the autumn, November, is another cool month in Sumner, Illinois, with an average temperature ranging between max 52.2°F (11.2°C) and min 37.9°F (3.3°C). November suggests a modest reduction in the average high-temperature, shifting from a refreshing 66°F (18.9°C) in October to a fresh 52.2°F (11.2°C). Weather in November »Weather in December
The first month of the winter, December, is still a cold month in Sumner, Illinois, with an average temperature varying between 30.9°F (-0.6°C) and 41.9°F (5.5°C). A subtle decrease in the average high-temperature marks December, falling from November's fresh 52.2°F (11.2°C) to a cold 41.9°F (5.5°C). Weather in December »Updated: Feb 12, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Sumner witnesses the coldest weather in January, with temperatures averaging a high of 36.7°F (2.6°C) and a low of 24.4°F (-4.2°C).
In Sumner, during the entire year, the rain falls for 160.3 days and collects up to 34.33" (872mm) of precipitation.
Months with snowfall are January through April, November and December.
The month with the most snowfall in Sumner is January, when snow falls for 6.8 days and typically aggregates up to 1.69" (43mm) of snow.
Throughout the year, in Sumner, there are 21.7 snowfall days, and 5.87" (149mm) of snow is accumulated.
The month with the least sunshine is January, with an average of 4.4h of sunshine.
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Sumner, Illinois.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Sumner, Illinois, 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.
April is the month with the most rainfall in Sumner, Illinois. Rain falls for 15.8 days and accumulates 4.69" (119mm) of precipitation.
May through October are months without snowfall.
The month with the longest days is June, with an average of 14h and 48min of daylight.
June has the most sunshine of the year in Sumner, with an average of 10.6h of sunshine.
June through August, with an average maximum UV index of 6, are months with the highest UV index.
Sumner's warmest temperatures are experienced in July, with average high temperatures of 84°F (28.9°C) and lows of 67.3°F (19.6°C).
With an average relative humidity of 81%, July is the most humid month in Sumner.
September is the month with the least rainfall. Rain falls for 13.1 days and accumulates 1.93" (49mm) of precipitation.
October is the least humid month, with an average relative humidity of 70%.
December has the shortest days of the year, with an average of 9h and 30min of daylight.
Average temperature
Sumner, IL
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (36.7°F).
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (24.4°F).
Average pressure
Sumner, IL
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.96"Hg - Average pressure in May:
29.97"Hg - Average pressure in June:
29.94"Hg
- Average pressure in July:
29.98"Hg - Average pressure in August:
29.99"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.14"Hg - Average pressure in December:
30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed
Sumner, IL
- Average wind speed in January:
10mph - Average wind speed in February:
10.1mph - Average wind speed in March:
9.9mph - Average wind speed in April:
9.8mph - Average wind speed in May:
8.2mph - Average wind speed in June:
7mph
- Average wind speed in July:
5.8mph - Average wind speed in August:
5.9mph - Average wind speed in September:
6.7mph - Average wind speed in October:
8.6mph - Average wind speed in November:
9.1mph - Average wind speed in December:
9.3mph
The windiest month (with the highest average wind speed) is February (10.1mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity
Sumner, IL
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (70%).
Average rainfall
Sumner, IL
- Average rainfall in January:
2.4" - Average rainfall in February:
2.2" - Average rainfall in March:
2.91" - Average rainfall in April:
4.69" - Average rainfall in May:
3.62" - Average rainfall in June:
3.54"
- Average rainfall in July:
3.11" - Average rainfall in August:
2.36" - Average rainfall in September:
1.93" - Average rainfall in October:
2.44" - Average rainfall in November:
2.52" - Average rainfall in December:
2.6"
The wettest month (with the highest rainfall) is April (4.69").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days
Sumner, IL
- Average rainfall days in January:
9.5 days - Average rainfall days in February:
9.4 days - Average rainfall days in March:
15.3 days - Average rainfall days in April:
15.8 days - Average rainfall days in May:
19.6 days - Average rainfall days in June:
15.1 days
- Average rainfall days in July:
16.8 days - Average rainfall days in August:
13.5 days - Average rainfall days in September:
13.1 days - Average rainfall days in October:
11.3 days - Average rainfall days in November:
10.4 days - Average rainfall days in December:
10.5 days
The month with the highest number of rainy days is May (19.6 days).
The month with the least rainy days is February (9.4 days).
Average snowfall
Sumner, IL
The month with the highest snowfall is January (1.69").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Sumner, IL
- Average snowfall days in January:
6.8 days - Average snowfall days in February:
6.4 days - Average snowfall days in March:
2.5 days - Average snowfall days in April:
0.3 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 days - Average snowfall days in November:
1.4 days - Average snowfall days in December:
4.3 days
The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Sumner, IL
- Average daylight in January:
9h and 48min - Average daylight in February:
10h and 48min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 12min - Average daylight in May:
14h and 18min - Average daylight in June:
14h and 48min
- Average daylight in July:
14h and 36min - Average daylight in August:
13h and 36min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 12min - Average daylight in November:
10h and 6min - Average daylight in December:
9h and 30min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in January:
4h and 24min - Average sunshine in February:
4h and 36min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 30min - Average sunshine in May:
9h and 6min - Average sunshine in June:
10h and 36min
- Average sunshine in July:
10h and 24min - Average sunshine in August:
10h and 24min - Average sunshine in September:
9h and 6min - Average sunshine in October:
6h and 48min - Average sunshine in November:
5h and 30min - Average sunshine in December:
4h and 30min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days
Sumner, IL
- Average sunshine days in January:
16.1 days - Average sunshine days in February:
12.8 days - Average sunshine days in March:
12.7 days - Average sunshine days in April:
11.6 days - Average sunshine days in May:
9.4 days - Average sunshine days in June:
10.8 days
- Average sunshine days in July:
10.9 days - Average sunshine days in August:
15.1 days - Average sunshine days in September:
15.3 days - Average sunshine days in October:
18 days - Average sunshine days in November:
17.2 days - Average sunshine days in December:
16 days
The month with the most sunshine days is October (18 days).
The month with the least sunshine days is May (9.4 days).
Average UV index
Sumner, 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
Sumner, IL
The month with the most cloud cover is January (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility
Sumner, IL
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
