Climate and monthly weather forecast
Wheaton, IL


The climate of Wheaton

Set within the Midwest of the United States in the state of Illinois, Wheaton features a Dfa - Humid Continental climate classification according to Köppen climatic zones. Essentially, this climate type is characterized by no dry season with hot summers bringing an inviting contrast to the cold winters.

Throughout the year, there's a significant variation in the temperature spectrum of Wheaton, Illinois. The highest temperatures are enjoyed in the summer months with averages reaching the peak of 81.7°F (27.6°C) in July, while the coldest averages are experienced in the heart of winter, dipping to a chilly 16.7°F (-8.5°C) in January.

A diversity is certainly prevalent when discussing the humidity levels of Wheaton. Levels fluctuate from 73% in October to a high of 83% in the beginning months of the year, January and February. Precipitation in the area spreads fairly equally throughout the year but is most frequent during the summer months, reaching its highest point in May with 4.45" (113mm) of rain. The sun shines brightest during high summer, with July and August boasting 9.8 to 9.9 hours of light-beaming days on average.

Unique weather conditions in Wheaton are surely represented by the snowfall. Although this weather phenomenon nearly disappears from May to September, snow showers highlight some months, with January displaying the heaviest snowfall reaching up to 5.87" (149mm).

The Best Time to Visit Wheaton

Visitors who appreciate warm weather should aim for a visit between June and August. The temperatures in these months comfortably sit within the range of 78.1°F (25.6°C) to 81.7°F (27.6°C). Additionally, these months also provide the longest daylight hours, amounting to 14.6 to 15.2 hours.

For those enamored by the sight of snowfall, January or February would be the ideal time to visit, given that these months encompass the majority of Wheaton's snowfall with 5.87" (149mm) and 5.12" (130mm) respectively.

The Worst Time to Visit Wheaton

January represents the coldest month in Wheaton with an average low temperature of 16.7°F (-8.5°C). Alongside this, it’s the month that witnesses the heaviest snowfall which could diminish outdoor activities. Hence it is not ideal for those who are not winter enthusiasts.

Spring Weather in Wheaton

When spring steps in from March to May, Wheaton experiences mild climatic conditions. The average high temperature escalates from 45°F (7.2°C) in March to reach 68.5°F (20.3°C) in May. Rainfall during this period registers from 1.97 to 4.45" (113mm). This season has the most rain, topping at an average of 19.2 days in May. Overall, it is a season that merges blooming nature with a refreshing climate.

Summer Weather in Wheaton

Summers in Wheaton, from June to August, are relatively warm with average high temperatures hitting between 78.1°F (25.6°C) and 81.7°F (27.6°C). Sunshine lasts from 8.5 to 9.8 hours and days are the longest of the year, offering abundant daylight from 14.9 to 15.2 hours. Rain occurs frequently; June sees the highest average rain with 4.29" (109mm). All the while, relative humidity ranges from 78% to 78%.

Autumn Weather in Wheaton

Autumn brings mellow weather in Wheaton between September and November. The average high temperature retreats from 73.6°F (23.1°C) to 45.5°F (7.5°C) as the season progresses. Rainfall lessens to 2.48" (63mm) in September before rising slightly to 2.83" (72mm) in October. September also hosts the highest temperature of the season while November welcomes the first snow of the season with 1.65" (42mm).

Winter Weather in Wheaton

Winters in Wheaton from December through to February are notable for their significant chill. The average high temperature fluctuates from 34.3°F (1.3°C) to 28°F (-2.2°C) while the average low temperature drifts between 24.3°F (-4.3°C) and 16.7°F (-8.5°C). Snow is a regular feature with February displaying up to 5.12" (130mm). These months also have the shortest sunlight period, ranging from 9.2 hours in December and dwindling further to 9.5 hours in January. Although winter may be bitter and layered in snow, its idyllic winter scenes create a beautiful and serene atmosphere.

Weather in January

Cold temperatures are the hallmark of Wheaton’s January weather. The temperature fluctuates between a chilling 28°F (-2.2°C) and a colder 16.7°F (-8.5°C), making it the coldest month of the year. The inclement weather extends to high snowfall levels, with residents experiencing a majority of the yearly snowfall this month. Weather in January »

Weather in February

February, the last month of the winter in Wheaton, is a wintry month, with an average temperature ranging between min 19.8°F (-6.8°C) and max 32.2°F (0.1°C). February's weather records an average high-temperature of a wintry 32.2°F (0.1°C), showing little deviation from January. Weather in February »

Weather in March

The first month of the spring, March, is a frosty month in Wheaton, Illinois, with temperature in the range of an average high of 45°F (7.2°C) and an average low of 30.7°F (-0.7°C). With the onset of March, Wheaton's weather sees a temperature rise, transitioning from an icy 32.2°F (0.1°C) in February to a frosty 45°F (7.2°C). Weather in March »

Weather in April

April in Wheaton is known for a significant rise in temperatures, high rainfall, and longer daylight hours. It features an apparent spike in rainfall, with 3.78" (96mm), ushering in the refreshing showers of springtime. As the temperatures steer clear of the freezing point, snowfall ceases. Weather in April »

Weather in May

May sees the full bloom of spring in Wheaton, with warmer temperatures and increasingly longer days. It marks the break from the cold weather, as temperatures range in the more pleasant high 60s°F. Sunlight envelopes most of the day, and a significant increase in UV index is noted. Weather in May »

Weather in June

June in Wheaton signals the start of summer, with hot temperatures and extended daylight hours. June experiences the highest UV index of 6, necessitating sun protection gear during outdoor activities. Rainfall in June remains slightly lesser than in May. Weather in June »

Weather in July

The peak of summer arrives in Wheaton in July. This month records the highest temperatures, ranging from 81.7°F (27.6°C) to 65.3°F (18.5°C). Relative humidity levels and daylight hours pretty much maintain the trend set in June. Weather in July »

Weather in August

August in Wheaton remains in the throes of summer with high temperatures, though there is a subtle drop from July. Rainfall diminishes by a small fraction, signaling the gradual end of the wet season. The beginning of the month usually enjoys long daylight hours, gradually decreasing towards the end of the month. Weather in August »

Weather in September

The arrival of autumn is noticeable in the September weather of Wheaton. A marked decrease occurs in temperature, taking a dip from summer's highs into the 70s°F. Rainfall continues to decrease from August, and September ranks the lowest in terms of rainfall quantity. Weather in September »

Weather in October

October in Wheaton is characterized by cooling temperatures, colorful fall foliage, and diminishing rainfall. October experiences the highest wind speed, with an average wind speed of 8.7mph (14km/h). Leaves changing colors and falling, combined with the crisp weather, do create a classic fall ambiance. Weather in October »

Weather in November

Winter begins to set its foot in November in Wheaton, with a notable drop in temperatures. November experiences a resurgence in rainfall, with a monthly average of 1.65" (42mm) of precipitation. The onset of the colder months brings a decline in the number of sunshine hours. Weather in November »

Weather in December

December in Wheaton brings about full-fledged winter conditions. The snow-filled, chilly December weather is characterized by temperatures alternating between a high of 34.3°F (1.3°C) and a low of 24.3°F (-4.3°C). Snowfall becomes a regular occurrence again, with December's average snowfall at 3.03" (77mm). Weather in December »

Frequently asked questions

What is the coldest time of year in Wheaton?

Wheaton, Illinois, reaches its average lowest temperatures in January, measuring 28°F (-2.2°C) at the peak and 16.7°F (-8.5°C) at the lowest.

What is the most humid month in Wheaton?

The months with the highest humidity are January and February, with an average relative humidity of 83%.

How many days does it rain in Wheaton?

In Wheaton, Illinois, during the entire year, the rain falls for 164.3 days and collects up to 33.78" (858mm) of precipitation.

When does it snow in Wheaton?

January through May, October through December are months with snowfall in Wheaton, Illinois.

When does it snow the most in Wheaton?

The month with the most snowfall in Wheaton is January, when snow falls for 13.1 days and typically aggregates up to 5.87" (149mm) of snow.

How much does it snow in Wheaton?

In Wheaton, during the entire year, snow falls for 47 days and aggregates up to 20.2" (513mm) of snow.

What is the month with the least sunshine in Wheaton?

With an average of 3.7h of sunshine, January has the least sunshine of the year in Wheaton, Illinois.

When is the lowest UV index in Wheaton?

January is the month with the lowest UV index, with an average maximum UV index of 1.

When is Daylight Saving Time (DST) in Wheaton?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Wheaton, 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.

What is the wettest month in Wheaton?

The month with the most rainfall is May, when the rain falls for 19.2 days and typically aggregates up to 4.45" (113mm) of precipitation.

When it does not snow in Wheaton?

In Wheaton, snow does not fall in June through September.

When are the longest days in Wheaton?

June has the longest days of the year, with an average of 15h and 12min of daylight.

What are the months with the highest UV index in Wheaton?

The months with the highest UV index are June through August, with an average maximum UV index of 6.

What part of the year is the hottest in Wheaton?

In Wheaton, temperatures reach their average annual highs in July, measuring 81.7°F (27.6°C) and a minimum average of 65.3°F (18.5°C).

What month has the most sunshine in Wheaton?

August has the most sunshine of the year in Wheaton, Illinois, with an average of 9.9h of sunshine.

What is the least humid month in Wheaton?

October is the least humid month, with an average relative humidity of 73%.

What is the driest month in Wheaton?

The months with the least rainfall in Wheaton are November and December Rain falls for 10.2 days and accumulates 1.65" (42mm) of rain.

What is the month with the shortest days in Wheaton?

With an average of 9h and 12min of daylight, December has the shortest days of the year in Wheaton, Illinois.

Average pressure
Wheaton, IL

Average pressure - Wheaton, IL

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).


Average wind speed
Wheaton, IL

Average wind speed - Wheaton, IL

The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest month (with the lowest average wind speed) is August (6mph).


Average humidity
Wheaton, IL

Average humidity - Wheaton, IL

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (73%).


Average rainfall
Wheaton, IL

Average rainfall - Wheaton, IL

The wettest month (with the highest rainfall) is May (4.45").
The driest months (with the least rainfall) are November and December (1.65").


Average rainfall days
Wheaton, IL

Average rainfall days - Wheaton, IL

The month with the highest number of rainy days is July (20.1 days).
The month with the least rainy days is February (5.8 days).


Average snowfall
Wheaton, IL

Average snowfall - Wheaton, IL

The month with the highest snowfall is January (5.87").
The months with the least snowfall are June, July, August and September (0").


Average snowfall days
Wheaton, IL

Average snowfall days - Wheaton, IL

The month with the highest number of snowfall days is January (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).


Average daylight / Average sunshine
Wheaton, IL

Average daylight / Average sunshine - Wheaton, IL

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).

The month with the most sunshine is August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).


Average sunshine days
Wheaton, IL

Average sunshine days - Wheaton, IL

The month with the most sunshine days is November (16.1 days).
The month with the least sunshine days is July (8.2 days).


Average visibility
Wheaton, IL

Average visibility - Wheaton, IL

The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).


Wheaton, Illinois, USA

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