Climate and monthly weather forecast
Rock Falls, IL

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Weather in January

January, like December, is a freezing cold winter month in Rock Falls, Illinois, with an average temperature varying between 14.9°F (-9.5°C) and 27.7°F (-2.4°C). January is the coldest month of the year, registering average temperatures as high as 27.7°F (-2.4°C) and as low as 14.9°F (-9.5°C). Weather in January »

Weather in February

February, the last month of the winter in Rock Falls, is another freezing cold month, with an average temperature varying between 18.5°F (-7.5°C) and 31.6°F (-0.2°C). Rock Falls sees the arrival of February with an average high-temperature of a still freezing cold 31.6°F (-0.2°C), indicating a subtle variation from January. Weather in February »

Weather in March

The first month of the spring, March, is a frosty month in Rock Falls, Illinois, with an average temperature ranging between min 31.3°F (-0.4°C) and max 45.9°F (7.7°C). Rock Falls in March sees a temperature change, with average high-temperatures moving from a freezing cold 31.6°F (-0.2°C) in February to a chilly 45.9°F (7.7°C). Weather in March »

Weather in April

April is a mild spring month in Rock Falls, Illinois, with an average temperature ranging between max 57.9°F (14.4°C) and min 41.4°F (5.2°C). April brings a rise in the average high-temperature, transitioning from March's chilly 45.9°F (7.7°C) to a moderate 57.9°F (14.4°C). Weather in April »

Weather in May

May, the last month of the spring in Rock Falls, is an agreeable month, with an average temperature fluctuating between 69.4°F (20.8°C) and 52.5°F (11.4°C). With the onset of May, Rock Falls's weather sees a temperature rise, transitioning from a moderate 57.9°F (14.4°C) in April to a pleasant 69.4°F (20.8°C). Weather in May »

Weather in June

June, the first month of the summer in Rock Falls, is a moderately hot month, with an average temperature ranging between max 78.3°F (25.7°C) and min 61.3°F (16.3°C). The onset of June marks a slight increase in the average high-temperature, moving from a pleasant 69.4°F (20.8°C) in May to a warm 78.3°F (25.7°C). Weather in June »

Weather in July

July, the same as June, is another warm summer month in Rock Falls, Illinois, with an average temperature fluctuating between 80.2°F (26.8°C) and 63.9°F (17.7°C). Rock Falls, Illinois, experiences its highest average temperatures in July, reaching a peak of 80.2°F (26.8°C) and a minimum of 63.9°F (17.7°C). Weather in July »

Weather in August

August, the last month of the summer in Rock Falls, is also a moderately hot month, with an average temperature fluctuating between 79.3°F (26.3°C) and 61.7°F (16.5°C). August brings an average high-temperature of a still moderately hot 79.3°F (26.3°C), nearly identical to the preceding month. Weather in August »

Weather in September

September, the first month of the autumn in Rock Falls, is still a warm month, with temperature in the range of an average high of 73.9°F (23.3°C) and an average low of 55.2°F (12.9°C). In September, the meteorological conditions change slightly, with the average high-temperature moving from 79.3°F (26.3°C) in August to a still moderately hot 73.9°F (23.3°C). Weather in September »

Weather in October

October, the same as September, in Rock Falls, Illinois, is a moderate autumn month, with an average temperature ranging between max 60.6°F (15.9°C) and min 44.6°F (7°C). In October, the average high-temperature goes from a warm 73.9°F (23.3°C) in September to a mild 60.6°F (15.9°C). Weather in October »

Weather in November

November, the last month of the autumn in Rock Falls, is also a frosty month, with an average temperature ranging between min 32.4°F (0.2°C) and max 45.5°F (7.5°C). November's arrival signals a distinct temperature shift, dropping from a moderate 60.6°F (15.9°C) in October to a chilly 45.5°F (7.5°C). Weather in November »

Weather in December

December, the first month of the winter in Rock Falls, is still a cold month, with an average temperature fluctuating between 23.2°F (-4.9°C) and 33.8°F (1°C). The commencement of December involves a temperature shift, with the average high-temperature dropping from a frosty 45.5°F (7.5°C) in November to a cold 33.8°F (1°C). Weather in December »
Updated: Aug 27, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest month?

Rock Falls experiences its average lowest temperatures in January, reaching a peak of 27.7°F (-2.4°C) and a minimum of 14.9°F (-9.5°C).

What is the most humid month?

January and July, with an average relative humidity of 85%, are most humid months.

What is the driest month?

The months with the least rainfall are January and February Rain falls for 4.8 days and accumulates 0.75" (19mm) of rain.

How much does it rain?

In Rock Falls, during the entire year, the rain falls for 130.2 days and collects up to 17.36" (441mm) of precipitation.

When does it snow?

January through April, October through December are months with snowfall.

When does it snow the most?

January is the month with the most snowfall. Snow falls for 10.2 days and accumulates 2.56" (65mm) of snow.

How much does it snow?

Throughout the year, in Rock Falls, there are 34.2 snowfall days, and 7.87" (200mm) of snow is accumulated.

What is the month with the least sunshine?

With an average of 3.8h of sunshine, January has the least sunshine of the year.

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?

The month with the most rainfall is May, when the rain falls for 17.3 days and typically aggregates up to 2.83" (72mm) of precipitation.

When it does not snow?

May through September are months without snowfall.

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 warmest month in Rock Falls?

The warmest time of the year is July, with temperatures averaging a high of 80.2°F (26.8°C) and a low of 63.9°F (17.7°C).

What month has the most sunshine?

The month with the most sunshine is July, with an average of 9.8h of sunshine.

What is the month with the highest UV index?

With an average maximum UV index of 6, July is the month with the highest UV index.

What is the least humid month?

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

What is the month with the shortest days?

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

What is the month with the lowest UV index?

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

Average temperature
Rock Falls, IL

Average temperature - Rock Falls, IL

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27.7°F).

The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (14.9°F).

Average pressure
Rock Falls, IL

Average pressure - Rock Falls, IL

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed
Rock Falls, IL

Average wind speed - Rock Falls, IL

The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity
Rock Falls, IL

Average humidity - Rock Falls, IL

The months with the highest relative humidity are January and July (85%).
The month with the lowest relative humidity is October (73%).

Average rainfall
Rock Falls, IL

Average rainfall - Rock Falls, IL

The wettest month (with the highest rainfall) is May (2.83").
The driest months (with the least rainfall) are January and February (0.75").

Average rainfall days
Rock Falls, IL

Average rainfall days - Rock Falls, IL

The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (4.8 days).

Average snowfall
Rock Falls, IL

Average snowfall - Rock Falls, IL

The month with the highest snowfall is January (2.56").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days
Rock Falls, IL

Average snowfall days - Rock Falls, IL

The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight / Average sunshine
Rock Falls, IL

Average daylight / Average sunshine - Rock Falls, 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 July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days
Rock Falls, IL

Average sunshine days - Rock Falls, IL

The months with the most sunshine days are November and December (18.8 days).
The month with the least sunshine days is June (11.3 days).

Average visibility
Rock Falls, IL

Average visibility - Rock Falls, 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).

Rock Falls, Illinois, USA

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