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

Monthly weather forecast and climate
Harrisburg, IL

January, like December, in Harrisburg, Illinois, is another cold winter month, with temperature in the range of an average high of 39.7°F (4.3°C) and an average low of 26.2°F (-3.2°C). January is the coldest month, with an average high-temperature of 39.7°F (4.3°C) and an average low-temperature of 26.2°F (-3.2°C). Weather in January »

The last month of the winter, February, is a frosty month in Harrisburg, Illinois, with average temperature ranging between min 30.2°F (-1°C) and max 44.1°F (6.7°C). In February, the average high-temperature is almost the same as in January - a frosty 44.1°F (6.7°C). Weather in February »

March, the first month of the spring, in Harrisburg, is a cool month, with average temperature varying between 39.2°F (4°C) and 55°F (12.8°C). In Harrisburg, the average high-temperature increases, from a frosty 44.1°F (6.7°C) in February, to a cool 55°F (12.8°C). Weather in March »

April is a comfortable spring month in Harrisburg, Illinois, with average temperature fluctuating between 66.4°F (19.1°C) and 48.7°F (9.3°C). In Harrisburg, the average high-temperature rises, from a cool 55°F (12.8°C) in March, to a comfortable 66.4°F (19.1°C). Weather in April »

The last month of the spring, May, is a moderately hot month in Harrisburg, Illinois, with average temperature fluctuating between 58.1°F (14.5°C) and 75.6°F (24.2°C). In May, the average high-temperature rises, from an enjoyable 66.4°F (19.1°C) in April, to a warm 75.6°F (24.2°C). Weather in May »

June, the first month of the summer, in Harrisburg, is still a warm month, with temperature in the range of an average low of 66.2°F (19°C) and an average high of 84.7°F (29.3°C). In June, the average high-temperature increases, from 75.6°F (24.2°C) in May, to a still moderately hot 84.7°F (29.3°C). Weather in June »

July in Harrisburg, Illinois, is a hot summer month, with average temperature varying between 87.3°F (30.7°C) and 68.5°F (20.3°C). With an average high-temperature of 87.3°F (30.7°C) and an average low-temperature of 68.5°F (20.3°C), July is the warmest month. The average heat index is evaluated at a sweltering 102°F (38.9°C). Weather in July »

The last month of the summer, August, is also a moderately hot month in Harrisburg, Illinois, with average temperature fluctuating between 66°F (18.9°C) and 85.6°F (29.8°C). In Harrisburg, Illinois, the average high-temperature in August is essentially the same as in July - a warm 85.6°F (29.8°C). Weather in August »

September, the first month of the autumn, in Harrisburg, is also a moderately hot month, with average temperature ranging between min 60.4°F (15.8°C) and max 80.8°F (27.1°C). In Harrisburg, Illinois, the average high-temperature is essentially the same as in August - a still warm 80.8°F (27.1°C). Weather in September »

October, like September, in Harrisburg, Illinois, is another comfortable autumn month, with temperature in the range of an average high of 67.8°F (19.9°C) and an average low of 49.3°F (9.6°C). In Harrisburg, the average high-temperature drops, from a warm 80.8°F (27.1°C) in September, to an enjoyable 67.8°F (19.9°C). Weather in October »

The last month of the autumn, November, is another cool month in Harrisburg, Illinois, with average temperature ranging between min 38.7°F (3.7°C) and max 53.8°F (12.1°C). In Harrisburg, the average high-temperature in November drops, from an enjoyable 67.8°F (19.9°C) in October, to a cool 53.8°F (12.1°C). Weather in November »

December, the first month of the winter, in Harrisburg, is also a frosty month, with average temperature varying between 44.1°F (6.7°C) and 32.4°F (0.2°C). In December, the average high-temperature decreases, from a fresh 53.8°F (12.1°C) in November, to a chilly 44.1°F (6.7°C). Weather in December »

What is the coldest month in Harrisburg?

With an average high-temperature of 39.7°F (4.3°C) and an average low-temperature of 26.2°F (-3.2°C), January is the coldest month in Harrisburg.

How much does it rain in Harrisburg?

In Harrisburg, Illinois, during the entire year, the rain falls for 158.6 days and collects up to 36.02" (915mm) of precipitation.

When does it snow in Harrisburg?

Months with snowfall in Harrisburg are January through April, October through December.

How many days does it snow in Harrisburg?

In Harrisburg, Illinois, during the entire year, snow falls for 17.7 days, and aggregates up to 6.57" (167mm) of snow.

What is the snowiest month in Harrisburg?

The month with the most snowfall is January when snow falls for 5.3 days and typically aggregates up to 1.73" (44mm) of snow.

What is the month with the least sunshine in Harrisburg?

January has the least sunshine of the year in Harrisburg, with an average of 4.6h of sunshine.

When is the lowest UV index in Harrisburg?

Months with the lowest UV index in Harrisburg, Illinois, are January, February and December, with an average maximum UV index of 2.

What is the wettest month in Harrisburg?

The month with the most rainfall is April when the rain falls for 16.6 days and typically aggregates up to 4.8" (122mm) of precipitation.

What is the most humid month in Harrisburg?

The most humid month is May, with an average relative humidity of 79%.

When it does not snow in Harrisburg?

May through September are months without snowfall in Harrisburg.

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

Months with the highest UV index in Harrisburg, Illinois, are May through August, with an average maximum UV index of 6.

When are the longest days in Harrisburg?

June has the longest days of the year in Harrisburg, Illinois, with an average of 14.7h of daylight.

What month has the most sunshine in Harrisburg?

June has the most sunshine of the year in Harrisburg, with an average of 10.6h of sunshine.

What is the warmest month in Harrisburg?

With an average high-temperature of 87.3°F (30.7°C) and an average low-temperature of 68.5°F (20.3°C), July is the warmest month in Harrisburg, Illinois.

What is the driest month in Harrisburg?

The month with the least rainfall is September when the rain falls for 10.5 days and typically collects 1.57" (40mm) of precipitation.

What is the least humid month in Harrisburg?

October is the least humid month in Harrisburg, Illinois, with an average relative humidity of 70%.

What is the month with the shortest days in Harrisburg?

December has the shortest days of the year, with an average of 9.6h of daylight.
Average temperature - Harrisburg, IL
Average rainfall - Harrisburg, IL

The wettest month (with the highest rainfall) is April (4.8").
The driest month (with the lowest rainfall) is September (1.57").

Average rainfall days - Harrisburg, IL

The month with the highest number of rainy days is May (18.5 days).
The month with the lowest number of rainy days is November (9.7 days).

Average snowfall - Harrisburg, IL
Average snowfall days - Harrisburg, IL

The month with the highest number of snowfall days is January (5.3 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average daylight / Average sunshine - Harrisburg, IL

The month with the longest days is June (Average daylight: 14.7h).
The month with shortest days is December (Average daylight: 9.6h).

The month with most sunshine is June (Average sunshine: 10.6h).
The month with least sunshine is January (Average sunshine: 4.6h).

Average UV index - Harrisburg, IL