Climate and monthly weather forecast
Monmouth, IL

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Weather in January

January, the same as December, in Monmouth, Illinois, is another subzero cold winter month, with temperature in the range of an average high of 29.7°F (-1.3°C) and an average low of 17.6°F (-8°C). The coldest temperatures occur during January, when averages reach a peak of 29.7°F (-1.3°C) and a low of 17.6°F (-8°C). Weather in January »

Weather in February

The last month of the winter, February, is a cold month in Monmouth, Illinois, with temperature in the range of an average low of 21.6°F (-5.8°C) and an average high of 34.9°F (1.6°C). Monmouth registers an average high-temperature of a wintry 34.9°F (1.6°C) at the commencement of February, closely related to the preceding month. Weather in February »

Weather in March

The first month of the spring, March, is a chilly month in Monmouth, Illinois, with an average temperature varying between 48°F (8.9°C) and 33.3°F (0.7°C). March sees a rise in the average high-temperature, climbing from a wintry 34.9°F (1.6°C) in February to a frosty 48°F (8.9°C). Weather in March »

Weather in April

April is a mild spring month in Monmouth, Illinois, with temperature in the range of an average low of 43.3°F (6.3°C) and an average high of 60.4°F (15.8°C). Observing a rise in April, the average high-temperature goes from March's frosty 48°F (8.9°C) to a refreshing 60.4°F (15.8°C). Weather in April »

Weather in May

The last month of the spring, May, is an agreeable month in Monmouth, Illinois, with temperature in the range of an average high of 70.9°F (21.6°C) and an average low of 54.1°F (12.3°C). As Monmouth, Illinois, enters May, the average high-temperature increases from the a refreshing 60.4°F (15.8°C) of April to a pleasant 70.9°F (21.6°C). Weather in May »

Weather in June

June, the first month of the summer in Monmouth, is a moderately hot month, with temperature in the range of an average high of 79.5°F (26.4°C) and an average low of 63.1°F (17.3°C). With the onset of June, Monmouth's average high-temperature sees a modest rise, moving from May's pleasant 70.9°F (21.6°C) to a moderately hot 79.5°F (26.4°C). Weather in June »

Weather in July

July, the same as June, is a moderately hot summer month in Monmouth, Illinois, with an average temperature ranging between min 64.9°F (18.3°C) and max 82°F (27.8°C). July is the warmest month, exhibiting average temperatures of 82°F (27.8°C) at the peak and 64.9°F (18.3°C) at the base. July's heat index is computed to be a hot 89.6°F (32°C). Weather in July »

Weather in August

August, the last month of the summer in Monmouth, is also a moderately hot month, with an average temperature fluctuating between 81.1°F (27.3°C) and 63.3°F (17.4°C). The shift to August signals an average high-temperature of a still warm 81.1°F (27.3°C), subtly varied from July's 82°F (27.8°C). Weather in August »

Weather in September

September, the first month of the autumn in Monmouth, is also a moderately hot month, with an average temperature fluctuating between 56.3°F (13.5°C) and 75.9°F (24.4°C). In September, the average high-temperature registers at a still moderately hot 75.9°F (24.4°C), nearly identical to August's 81.1°F (27.3°C). Weather in September »

Weather in October

October, like September, in Monmouth, Illinois, is another refreshing autumn month, with an average temperature ranging between max 61.7°F (16.5°C) and min 45.9°F (7.7°C). In Monmouth, the average high-temperature in October decreases from a warm 75.9°F (24.4°C) in September to an enjoyable 61.7°F (16.5°C). Weather in October »

Weather in November

November, the last month of the autumn in Monmouth, is another chilly month, with an average temperature ranging between max 47.5°F (8.6°C) and min 34°F (1.1°C). November comes with a decrease in the average high-temperature, falling from an enjoyable 61.7°F (16.5°C) in October to a frosty 47.5°F (8.6°C). Weather in November »

Weather in December

The first month of the winter, December, is still a cold month in Monmouth, Illinois, with temperature in the range of an average high of 35.6°F (2°C) and an average low of 24.6°F (-4.1°C). Monmouth's December weather features a mild decline in high-temperatures, reducing from a frosty 47.5°F (8.6°C) in November to an icy 35.6°F (2°C). Weather in December »
Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest month?

January, characterized by an average high temperature of 29.7°F (-1.3°C) and a low temperature of 17.6°F (-8°C), is generally the coldest month.

What is the driest month?

The month with the least rainfall is January, when the rain falls for 5.9 days and typically collects 1.46" (37mm) of precipitation.

How many days does it rain in Monmouth?

In Monmouth, during the entire year, the rain falls for 149.4 days and collects up to 30.16" (766mm) of precipitation.

When does it snow?

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

What is the snowiest month?

January is the month with the most snowfall. Snow falls for 10.9 days and accumulates 4.61" (117mm) of snow.

How many days does it snow in Monmouth?

Throughout the year, there are 36.7 snowfall days, and 15.31" (389mm) of snow is accumulated.

What is the month with the least sunshine?

With an average of 4.1h of sunshine, January has the least sunshine of the year.

What is the month with the lowest UV index?

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

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 wettest month?

May is the month with the most rainfall. Rain falls for 19 days and accumulates 4.25" (108mm) 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 6min of daylight.

What month has the most sunshine in Monmouth?

June has the most sunshine of the year, with an average of 10.1h of sunshine.

What is the month with the highest UV index?

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

What month is the hottest?

July, with average temperatures reaching a high of 82°F (27.8°C) and a low of 64.9°F (18.3°C), is the warmest month.

What is the most humid month?

The most humid month in Monmouth is July, with an average relative humidity of 84%.

What is the least humid month?

The least humid month is October, with an average relative humidity of 71%.

What is the month with the shortest days?

With an average of 9h and 18min of daylight, December has the shortest days of the year.

Average temperature
Monmouth, IL

Average temperature - Monmouth, IL

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (29.7°F).

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.6°F).

Average pressure
Monmouth, IL

Average pressure - Monmouth, IL

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed
Monmouth, IL

Average wind speed - Monmouth, IL

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

Average humidity
Monmouth, IL

Average humidity - Monmouth, IL

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).

Average rainfall
Monmouth, IL

Average rainfall - Monmouth, IL

The wettest month (with the highest rainfall) is May (4.25").
The driest month (with the least rainfall) is January (1.46").

Average rainfall days
Monmouth, IL

Average rainfall days - Monmouth, IL

The month with the highest number of rainy days is May (19 days).
The month with the least rainy days is February (5.8 days).

Average snowfall
Monmouth, IL

Average snowfall - Monmouth, IL

The month with the highest snowfall is January (4.61").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days
Monmouth, IL

Average snowfall days - Monmouth, IL

The month with the highest number of snowfall days is January (10.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight / Average sunshine
Monmouth, IL

Average daylight / Average sunshine - Monmouth, IL

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days
Monmouth, IL

Average sunshine days - Monmouth, IL

The month with the most sunshine days is November (18 days).
The month with the least sunshine days is June (9.2 days).

Average visibility
Monmouth, IL

Average visibility - Monmouth, IL

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

Monmouth, Illinois, USA

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