Expand
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, like December, in Williamsville, Illinois, is another cold winter month, with an average temperature varying between 20.8°F (-6.2°C) and 33.1°F (0.6°C). January is the month when Williamsville experiences its coldest temperatures, averaging a high of 33.1°F (0.6°C) and a low of 20.8°F (-6.2°C). Weather in January »
Weather in February
The last month of the winter, February, is also an icy month in Williamsville, Illinois, with an average temperature varying between 37.9°F (3.3°C) and 25°F (-3.9°C). February's weather records an average high-temperature of a still cold 37.9°F (3.3°C), showing little deviation from January. Weather in February »
Weather in March
March, the first month of the spring in Williamsville, is a fresh month, with an average temperature varying between 35.6°F (2°C) and 51.1°F (10.6°C). Williamsville in March sees a temperature change, with average high-temperatures moving from a wintry 37.9°F (3.3°C) in February to a cool 51.1°F (10.6°C). Weather in March »
Weather in April
April is an enjoyable spring month in Williamsville, Illinois, with an average temperature ranging between max 63.1°F (17.3°C) and min 46.2°F (7.9°C). The arrival of April signals an increase in the average high-temperature, moving from a cool 51.1°F (10.6°C) in March to a comfortable 63.1°F (17.3°C). Weather in April »
Weather in May
May, the last month of the spring in Williamsville, is an agreeable month, with an average temperature varying between 72.9°F (22.7°C) and 56.5°F (13.6°C). An upsurge in temperatures occurs as April gives way to May, with average highs shifting from a comfortable 63.1°F (17.3°C) to a pleasant 72.9°F (22.7°C). Weather in May »
Weather in June
June, the first month of the summer in Williamsville, is a moderately hot month, with an average temperature varying between 81.1°F (27.3°C) and 64.4°F (18°C). Williamsville's weather in June shows a minor rise in the average high-temperature, moving slightly up from May's pleasant 72.9°F (22.7°C) to a moderately hot 81.1°F (27.3°C). Weather in June »
Weather in July
July, like June, in Williamsville, Illinois, is a moderately hot summer month, with an average temperature fluctuating between 66°F (18.9°C) and 82.8°F (28.2°C). Williamsville's temperature records reveal July as the warmest month, marked by average highs of 82.8°F (28.2°C) and lows of 66°F (18.9°C). In July, the average heat index is calculated to be a tropical 91.4°F (33°C). Weather in July »
Weather in August
The last month of the summer, August, is another warm month in Williamsville, Illinois, with temperature in the range of an average low of 64°F (17.8°C) and an average high of 81.7°F (27.6°C). The arrival of August brings an average high-temperature of a still warm 81.7°F (27.6°C), nearly identical to July's 82.8°F (28.2°C). Weather in August »
Weather in September
September, the first month of the autumn in Williamsville, is still a warm month, with an average temperature fluctuating between 77.2°F (25.1°C) and 58.5°F (14.7°C). September observes an average high-temperature of a still warm 77.2°F (25.1°C), marking an insignificant difference from August's 81.7°F (27.6°C). Weather in September »
Weather in October
October, the same as September, is another refreshing autumn month in Williamsville, Illinois, with temperature in the range of an average low of 48.2°F (9°C) and an average high of 64°F (17.8°C). Williamsville in October demonstrates a small temperature transition, adjusting from an average high of a warm 77.2°F (25.1°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 Williamsville, is another cool month, with an average temperature fluctuating between 50°F (10°C) and 36.5°F (2.5°C). Williamsville's weather changes with the onset of November, slightly falling from a refreshing 64°F (17.8°C) in October to a fresh 50°F (10°C). Weather in November »
Weather in December
The first month of the winter, December, is also a wintry month in Williamsville, Illinois, with an average temperature fluctuating between 38.7°F (3.7°C) and 28.2°F (-2.1°C). December comes with a decrease in the average high-temperature, falling from a fresh 50°F (10°C) in November to an icy 38.7°F (3.7°C). Weather in December »
Updated: Jun 18, 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 time of the year is the coldest?
January stands out as Williamsville's coldest month, with temperatures ranging between an average high of 33.1°F (0.6°C) and a low of 20.8°F (-6.2°C).
How much does it rain?
Throughout the year, there are 131.5 rainfall days, and 18.54" (471mm) of precipitation is accumulated.
When does it snow?
Months with snowfall are January through April, November and December.
When does it snow the most?
January is the month with the most snowfall. Snow falls for 8 days and accumulates 1.81" (46mm) of snow.
How much does it snow?
In Williamsville, during the entire year, snow falls for 24.5 days and aggregates up to 5.51" (140mm) of snow.
What is the month with the least sunshine?
January has the least sunshine of the year, with an average of 4.1h of sunshine.
What is the month with the lowest UV index?
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
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 October are months without snowfall.
What is the rainiest month?
June is the month with the most rainfall. Rain falls for 14.6 days and accumulates 2.36" (60mm) of precipitation.
When are the longest days in Williamsville?
The month with the longest days is June, with an average of 15h and 0min of daylight.
What month has the most sunshine?
The month with the most sunshine is June, with an average of 10.4h of sunshine.
When is the highest UV index?
June through August, with an average maximum UV index of 6, are months with the highest UV index.
What part of the year is the hottest?
Temperature readings reach their annual highs in July, averaging 82.8°F (28.2°C) and a minimum average of 66°F (18.9°C).
What is the most humid month?
July is the most humid month, with an average relative humidity of 84%.
What is the least humid month?
The least humid month is October, with an average relative humidity of 70%.
What is the driest month in Williamsville?
The month with the least rainfall in Williamsville is December, when the rain falls for 6.6 days and typically collects 0.83" (21mm) of precipitation.
What is the month with the shortest days?
The month with the shortest days in Williamsville is December, with an average of 9h and 24min of daylight.
Average temperature
Williamsville, IL
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (33.1°F).
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure
Williamsville, IL
- Average pressure in January:
30.15"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.94"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:
29.98"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.12"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
Williamsville, IL
- Average wind speed in January:
10.4mph - Average wind speed in February:
10.3mph - Average wind speed in March:
10.1mph - Average wind speed in April:
10.4mph - Average wind speed in May:
8.6mph - Average wind speed in June:
7.3mph
- Average wind speed in July:
6.2mph - Average wind speed in August:
6.2mph - Average wind speed in September:
7.1mph - Average wind speed in October:
9.1mph - Average wind speed in November:
9.8mph - Average wind speed in December:
9.8mph
The windiest months (with the highest average wind speed) are January and April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity
Williamsville, IL
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall
Williamsville, IL
- Average rainfall in January:
1.06" - Average rainfall in February:
0.98" - Average rainfall in March:
1.34" - Average rainfall in April:
2.05" - Average rainfall in May:
2.09" - Average rainfall in June:
2.36"
- Average rainfall in July:
1.69" - Average rainfall in August:
1.89" - Average rainfall in September:
1.85" - Average rainfall in October:
1.46" - Average rainfall in November:
0.94" - Average rainfall in December:
0.83"
The wettest month (with the highest rainfall) is June (2.36").
The driest month (with the least rainfall) is December (0.83").
Average rainfall days
Williamsville, IL
- Average rainfall days in January:
5.8 days - Average rainfall days in February:
5.7 days - Average rainfall days in March:
11.5 days - Average rainfall days in April:
13.6 days - Average rainfall days in May:
17 days - Average rainfall days in June:
14.6 days
- Average rainfall days in July:
14.6 days - Average rainfall days in August:
12.8 days - Average rainfall days in September:
11.6 days - Average rainfall days in October:
9.5 days - Average rainfall days in November:
8.2 days - Average rainfall days in December:
6.6 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (5.7 days).
Average snowfall
Williamsville, IL
The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Williamsville, IL
- Average snowfall days in January:
8 days - Average snowfall days in February:
6.3 days - Average snowfall days in March:
3.3 days - Average snowfall days in April:
0.5 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:
0.1 days - Average snowfall days in November:
1.5 days - Average snowfall days in December:
4.8 days
The month with the highest number of snowfall days is January (8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Williamsville, 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:
15h and 0min
- 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: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in January:
4h and 1min - Average sunshine in February:
4h and 2min - Average sunshine in March:
6h and 3min - Average sunshine in April:
8h and 1min - Average sunshine in May:
9h and 2min - Average sunshine in June:
10h and 2min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 2min - Average sunshine in October:
6h and 1min - Average sunshine in November:
5h and 3min - Average sunshine in December:
4h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days
Williamsville, IL
- Average sunshine days in January:
19.3 days - Average sunshine days in February:
16.3 days - Average sunshine days in March:
16.2 days - Average sunshine days in April:
13.8 days - Average sunshine days in May:
11.5 days - Average sunshine days in June:
12.2 days
- Average sunshine days in July:
13.1 days - Average sunshine days in August:
14.7 days - Average sunshine days in September:
16.8 days - Average sunshine days in October:
20 days - Average sunshine days in November:
19.9 days - Average sunshine days in December:
20.5 days
The month with the most sunshine days is December (20.5 days).
The month with the least sunshine days is May (11.5 days).
Average UV index
Williamsville, 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
Williamsville, IL
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are June, August and September (Cloud cover 30).
Average visibility
Williamsville, 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).