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Contents
- The climate of Mount Prospect
- The best time to visit Mount Prospect
- The worst time to visit Mount Prospect
- Spring weather in Mount Prospect
- Summer weather in Mount Prospect
- Autumn weather in Mount Prospect
- Winter weather in Mount Prospect
- 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
The climate of Mount Prospect
Residing in the continental interior of the USA, Mount Prospect, Illinois falls under the Köppen climate classification as a Dfa zone. This designation translates to a 'Humid Continental' climate with no dry season and a hot summer.
Significant fluctuations in weather parameters are part and parcel of Mount Prospect's climate. High temperatures range from a chilly 28.2°F (-2.1°C) in the coldest month to a toasty 81.1°F (27.3°C) in the middle of summer. Meanwhile, low temperatures vary from 18°F (-7.8°C) in the depths of winter to a pleasant 66.4°F (19.1°C) at the height of summer.
Relative humidity hovers between a consistent 72% to 82%. Rainfall varies moderately throughout the year, peaking at 3.9" (99mm) in May and ebbing to 1.46" (37mm) by December. The town experiences around 82.9" (2106mm) of rain annually, well-distributed across an average of 159.7 days.
Winter months are characterized by frequent snowfalls with annual totals reaching 13.45" (342mm) across 43.6 days. Daylight is most plentiful during June, reaching up to 15.2 hours. The longest sunshine duration of up to 10.2 hours also occurs in the height of summer.
Wind speeds are consistent year-round, averaging between 6.5mph (10.5km/h) and 10.4mph (16.7km/h). Pressure readings remain steady throughout the year, averaging between 29.92" (760mm) to 30.11" (765mm).
Significant fluctuations in weather parameters are part and parcel of Mount Prospect's climate. High temperatures range from a chilly 28.2°F (-2.1°C) in the coldest month to a toasty 81.1°F (27.3°C) in the middle of summer. Meanwhile, low temperatures vary from 18°F (-7.8°C) in the depths of winter to a pleasant 66.4°F (19.1°C) at the height of summer.
Relative humidity hovers between a consistent 72% to 82%. Rainfall varies moderately throughout the year, peaking at 3.9" (99mm) in May and ebbing to 1.46" (37mm) by December. The town experiences around 82.9" (2106mm) of rain annually, well-distributed across an average of 159.7 days.
Winter months are characterized by frequent snowfalls with annual totals reaching 13.45" (342mm) across 43.6 days. Daylight is most plentiful during June, reaching up to 15.2 hours. The longest sunshine duration of up to 10.2 hours also occurs in the height of summer.
Wind speeds are consistent year-round, averaging between 6.5mph (10.5km/h) and 10.4mph (16.7km/h). Pressure readings remain steady throughout the year, averaging between 29.92" (760mm) to 30.11" (765mm).
The best time to visit Mount Prospect
Mid-May to September offers the most pleasant weather conditions for visitors, coinciding with the town's peak tourist season. During this period, maximum temperatures fluctuate between 65.8°F (18.8°C) to 81.1°F (27.3°C), while minimum temperatures range from 50.5°F (10.3°C) to 66.4°F (19.1°C). The relative humidity hovers around 76% to 77%. Tourists can expect the most daylight, as well as the longest sunshine duration during these months.
The worst time to visit Mount Prospect
The least favorable weather conditions in Mount Prospect can be expected from late November to early March. During this period, the lowest temperatures drop to 18°F (-7.8°C) and the highest barely scrape past 34.7°F (1.5°C). Snowfall is most frequent in December and January, with an average monthly snowfall reaching 2.52" (64mm) in December. The duration of daylight is also at its shortest during these months.
Spring weather in Mount Prospect
Spring, observed from March to May, sees a gradual rise in temperatures from a high of 43.5°F (6.4°C) to a more amiable 65.8°F (18.8°C). Mornings can still be cold with temperatures starting at 30.9°F (-0.6°C) in March warming to 50.5°F (10.3°C) by May. Rainfall starts to increase during spring, reaching a peak in May with a monthly average of 3.9" (99mm).
Summer weather in Mount Prospect
Summers are quite hot in Mount Prospect. From June to August, temperatures can peak at 81.1°F (27.3°C) while cooling to a minimum of 60.4°F (15.8°C). This season brings plentiful sunshine with up to 15.2 hours of daylight in June. Rainfall is consistent during the summer months with averages hovering around 3.66" (93mm) in June and 2.87" (73mm) in August.
Autumn weather in Mount Prospect
Autumn is featured by a swift decrease in temperatures between September and November. High temperatures fall from 73.2°F (22.9°C) in September to 45.5°F (7.5°C) by November. Rainfall during this time tapers, reaching a low point of 1.57" (40mm) in November. This season still enjoys a fair amount of sunshine, with daylight averaging 11.1 hours to 9.8 hours in November.
Winter weather in Mount Prospect
Winter in Mount Prospect is characterized by low temperatures, sparse daylight and frequent snowfall. High temperatures from December through February waver between 28.2°F (-2.1°C) and 34.7°F (1.5°C), while lows range from 18°F (-7.8°C) to 25°F (-3.9°C). Snowfall is most frequent in December with monthly averages peaking at 2.52" (64mm). The duration of daylight shortens rapidly in winter months, with averages ranging from 9.2 hours to 9.5 hours.
Weather in January
Mount Prospect, Illinois starts the year with chilly temperatures that are typical of midwestern winters. The chill is coupled with snowy conditions, seeing the most snowfall in the year at 4.96in. Commuting in such conditions requires careful planning as roads may be slippery. Weather in January »
Weather in February
February extends the cold spell that began in January, maintaining the chilly weather that defines winter in Mount Prospect. With a continued high humidity relative of 82%, the weather condition leads to drier skin. The city experiences less snowfall this month, signaling that winter is gradually yielding to spring. Weather in February »
Weather in March
As spring approaches, the crucial shift in Mount Prospect climate happens in March. The March weather marks the transition from the freezing winter to milder temperatures, and this shift is not gradual. Though there is still a possibility of a snowfall, the city enjoys fewer snow days than in previous months. Weather in March »
Weather in April
April sees a significant rise in temperature - a clear sign that spring has sprung in Mount Prospect. The month witnesses a sharp decrease in snowfall to just 2.52in, indicating a clear departure from the cold of winter. Despite an increase in rainfall, the combination of longer daylight hours and the glowing warmth from the sun makes April a delightful month. Weather in April »
Weather in May
May is the official advent of warmer weather in Mount Prospect. The snowfalls of the previous months are a distant memory, with only a trivial 0.08in snowfall on record. Spring flowers are in full bloom, painting the city in an array of colors. Weather in May »
Weather in June
Summer arrives in Mount Prospect in June with temperatures hitting a record high of 75.9°F (24.4°C). The city enjoys maximum daylight hours and an enviable 9.7 sunlit hours. Rainfall occurs frequently, but that does not dampen the ambiance vibrant with summery energy. Weather in June »
Weather in July
July is the peak of summer in Mount Prospect with temperature reaching a high of 81.1°F (27.3°C). The city also experiences the longest sunshine duration of 10.2 hours. The hot weather makes it a perfect time for swimming or water activities, promising a refreshing respite from the heat. Weather in July »
Weather in August
Though still warm, August brings a slight dip in temperature from July in Mount Prospect. The long hours of daylight and sunshine continue, keeping the summer vibes alive. The warm temperatures and rainfall in August create a humid atmosphere. Weather in August »
Weather in September
September signifies the start of the fall season in Mount Prospect, with a noticeable decrease in temperature. With no snowfall recorded, the weather is still warm without the scorching summer heat. With the advent of fall, the city begins to detox from the summer’s intense humidity. Weather in September »
Weather in October
October continues the descent into cooler weather for Mount Prospect and the first occurrence of snow after summer — a minimal 0.35in. As the transition from summer to winter continues, the city sees a moderate amount of rainfall. Weather in October »
Weather in November
November introduces Mount Prospect to the beginnings of winter with a dramatic drop in temperature. To add to this, snowfall doubles from the previous month, measuring 1.73in. There is less daylight and fewer sunlit hours, a clear indication of the impending winter. Weather in November »
Weather in December
December brings full-on winter to Mount Prospect with the lowest temperature of the year at 25°F (-3.9°C). Snowfall increases to 2.52in and the city experiences more snow days. Short, frosty days and long, cold nights become the norm. Weather in December »
Updated: Jul 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 month is the coldest?
January, having an average high-temperature of 28.2°F (-2.1°C) and an average low-temperature of 18°F (-7.8°C), is the coldest month.
What is the most humid month?
The months with the highest humidity are January and February, with an average relative humidity of 82%.
How much does it rain?
In Mount Prospect, during the entire year, the rain falls for 153.3 days and collects up to 30.12" (765mm) of precipitation.
When does it snow?
Months with snowfall in Mount Prospect are January through May, October through December.
What is the snowiest month?
January is the month with the most snowfall in Mount Prospect. Snow falls for 11.8 days and accumulates 4.96" (126mm) of snow.
How much does it snow?
Throughout the year, in Mount Prospect, there are 43.6 snowfall days, and 17.95" (456mm) of snow is accumulated.
What is the month with the least sunshine?
The month with the least sunshine is January, with an average of 3.7h of sunshine.
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.
What is the rainiest month?
May is the month with the most rainfall. Rain falls for 18 days and accumulates 3.9" (99mm) of precipitation.
When it does not snow?
In Mount Prospect, Illinois, snow does not fall in June through September.
When are the longest days?
June has the longest days of the year, with an average of 15h and 12min of daylight.
What is the month with the highest UV index?
June through August, with an average maximum UV index of 6, are months with the highest UV index.
What are the warmest months?
Mount Prospect records the warmest temperatures in July, averaging a high of 81.1°F (27.3°C) and a low of 66.4°F (19.1°C).
What month has the most sunshine?
July has the most sunshine of the year, with an average of 10.2h of sunshine.
What is the least humid month?
With an average relative humidity of 72%, October is the least humid month.
What is the driest month?
December is the month with the least rainfall. Rain falls for 8.5 days and accumulates 1.46" (37mm) of precipitation.
What is the month with the shortest days in Mount Prospect?
With an average of 9h and 12min of daylight, December has the shortest days of the year.
When is the lowest UV index?
December is the month with the lowest UV index, with an average maximum UV index of 1.
Average temperature
Mount Prospect, IL
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (28.2°F).
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure
Mount Prospect, IL
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.92"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"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.09"Hg
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
Mount Prospect, IL
- Average wind speed in January:
10.4mph - Average wind speed in February:
10.2mph - Average wind speed in March:
9.7mph - Average wind speed in April:
9.9mph - Average wind speed in May:
8.4mph - Average wind speed in June:
7.5mph
- Average wind speed in July:
6.7mph - Average wind speed in August:
6.5mph - Average wind speed in September:
7.7mph - Average wind speed in October:
9.3mph - Average wind speed in November:
9.9mph - Average wind speed in December:
9.7mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity
Mount Prospect, IL
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall
Mount Prospect, IL
- Average rainfall in January:
1.65" - Average rainfall in February:
1.61" - Average rainfall in March:
1.85" - Average rainfall in April:
3.54" - Average rainfall in May:
3.9" - Average rainfall in June:
3.66"
- Average rainfall in July:
3.15" - Average rainfall in August:
2.87" - Average rainfall in September:
2.24" - Average rainfall in October:
2.6" - Average rainfall in November:
1.57" - Average rainfall in December:
1.46"
The wettest month (with the highest rainfall) is May (3.9").
The driest month (with the least rainfall) is December (1.46").
Average rainfall days
Mount Prospect, IL
- Average rainfall days in January:
7 days - Average rainfall days in February:
5.6 days - Average rainfall days in March:
11 days - Average rainfall days in April:
16 days - Average rainfall days in May:
18 days - Average rainfall days in June:
17.2 days
- Average rainfall days in July:
17.7 days - Average rainfall days in August:
15.7 days - Average rainfall days in September:
13.2 days - Average rainfall days in October:
13.9 days - Average rainfall days in November:
9.5 days - Average rainfall days in December:
8.5 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is February (5.6 days).
Average snowfall
Mount Prospect, IL
- Average snowfall in January:
4.96" - Average snowfall in February:
4.41" - Average snowfall in March:
1.38" - Average snowfall in April:
2.52" - Average snowfall in May:
0.08" - Average snowfall in June:
0"
The month with the highest snowfall is January (4.96").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Mount Prospect, IL
- Average snowfall days in January:
11.8 days - Average snowfall days in February:
10.2 days - Average snowfall days in March:
5.8 days - Average snowfall days in April:
1.9 days - Average snowfall days in May:
0.1 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:
3.8 days - Average snowfall days in December:
9.5 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Mount Prospect, IL
- Average daylight in January:
9h and 3min - 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 4min - Average daylight in June:
15h and 1min
- Average daylight in July:
14h and 5min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 1min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 1min
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 4min - Average sunshine in February:
3h and 5min - Average sunshine in March:
6h and 0min - Average sunshine in April:
7h and 3min - Average sunshine in May:
8h and 3min - Average sunshine in June:
9h and 4min
- Average sunshine in July:
10h and 1min - Average sunshine in August:
10h and 1min - Average sunshine in September:
8h and 5min - Average sunshine in October:
5h and 3min - Average sunshine in November:
5h and 0min - Average sunshine in December:
4h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days
Mount Prospect, IL
- Average sunshine days in January:
13.6 days - Average sunshine days in February:
12.3 days - Average sunshine days in March:
14.3 days - Average sunshine days in April:
10.8 days - Average sunshine days in May:
11 days - Average sunshine days in June:
10.7 days
- Average sunshine days in July:
11.2 days - Average sunshine days in August:
12.4 days - Average sunshine days in September:
14.1 days - Average sunshine days in October:
14.9 days - Average sunshine days in November:
16.3 days - Average sunshine days in December:
15.7 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is June (10.7 days).
Average UV index
Mount Prospect, IL
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover
Mount Prospect, IL
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility
Mount Prospect, 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).
Mount Prospect, Illinois, USA
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