Naperville
Illinois, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
Naperville, IL

The scenic view of a covered bridge over a river along the famous Naperville Riverwalk in Naperville, Illinois, reflections in the below water
The scenic view of a covered bridge over a river along the famous Naperville Riverwalk in Naperville, Illinois, reflections in the below water
August, the last month of the summer, in Naperville, is also a moderately hot month, with temperature in the range of an average high of 80.1°F (26.7°C) and an average low of 63.5°F (17.5°C).

Temperature

In Naperville, the average high-temperature is practically the same as in July - a still warm 80.1°F (26.7°C). The average low-temperature, in Naperville, is 63.5°F (17.5°C).

Humidity

In Naperville, the average relative humidity in August is 79%.

Rainfall

In August, in Naperville, the rain falls for 15.3 days. Throughout August, 1.81" (46mm) of precipitation is accumulated. Throughout the year, there are 132.2 rainfall days, and 16.22" (412mm) of precipitation is accumulated.

Snowfall

In Naperville snow does not fall in May through September.

Daylight

In Naperville, the average length of the day in August is 13.8h.

Sunshine

Months with the most sunshine are July and August, with an average of 10h of sunshine.

UV index

June through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high health hazard from unsafe exposure to the UV radiation for the ordinary person.
Note: In August, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in August in Naperville?

In Naperville, Illinois, in August, the average high-temperature is 80.1°F (26.7°C), and the average low-temperature is 63.5°F (17.5°C).

What is the average humidity in August in Naperville?

In August, the average relative humidity in Naperville is 79%.

How much does it rain in Naperville in August?

In August, the rain falls for 15.3 days. Throughout August, 1.81" (46mm) of precipitation is accumulated.

When it does not snow in Naperville?

In Naperville snow does not fall in May through September.

How many hours of daylight does Naperville have in August?

In August, the average length of the day is 13.8h.

What are the months with the most sunshine in Naperville?

July and August, with an average of 10h of sunshine, are months with the most sunshine in Naperville.

How many hours of sunshine does Naperville have in August?

The average sunshine in August in Naperville is 10h.

When is the highest UV index in Naperville?

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

How high is the UV index in August in Naperville?

In Naperville, the average daily maximum UV index in August is 6. A UV Index reading of 6 to 7 represents a high health threat from the exposure to the Sun's UV rays.
Average temperature in August - Naperville, IL
  • Average high temperature in August: 26.7°C

The warmest month (with the highest average high temperature) is July (27.6°C).
The month with the lowest average high temperature is January (-2°C).

  • Average low temperature in August: 17.5°C

The month with the highest average low temperature is July (18.4°C).
The coldest month (with the lowest average low temperature) is January (-8.3°C).

Average humidity in August - Naperville, IL
  • Average humidity in August: 79%

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

Average rainfall in August - Naperville, IL
  • Average rainfall in August: 46mm

The wettest month (with the highest rainfall) is May (53mm).
The driest month (with the lowest rainfall) is December (18mm).

Average rainfall days in August - Naperville, IL
  • Average rainfall days in August: 15.3 days

The month with the highest number of rainy days is July (17.3 days).
The month with the lowest number of rainy days is February (4.4 days).

Average snowfall in August - Naperville, IL
  • Average snowfall in August: 0mm

The month with the highest snowfall is January (47mm).
Months with the lowest snowfall are May, June, July, August and September (0mm).

Average snowfall days in August - Naperville, IL
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (11.1 days).
Months with the lowest number of snowfall days are June, July, August and September (0 days).

Average daylight in August / Average sunshine in August - Naperville, IL
  • Average daylight in August: 13.8h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.2h).

  • Average sunshine in August: 10h

Months with most sunshine are July and August (Average sunshine: 10h).
The month with least sunshine is January (Average sunshine: 3.8h).

Average UV index in August - Naperville, IL
  • Average UV index in August: 6

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January and December (UV index 1).