Expand
Contents
- 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
Weather in January
January, like December, is another subzero cold winter month in Marietta, Illinois, with temperature in the range of an average high of 31.5°F (-0.3°C) and an average low of 19.4°F (-7°C). January, on average, is the coldest month, registering a high temperature of 31.5°F (-0.3°C) and a low of 19.4°F (-7°C). Weather in January »
Weather in February
The last month of the winter, February, is a wintry month in Marietta, Illinois, with temperature in the range of an average low of 23°F (-5°C) and an average high of 36.3°F (2.4°C). The average high-temperature in February, at a cold 36.3°F (2.4°C), reveals a modest deviation from January's 31.5°F (-0.3°C). Weather in February »
Weather in March
The first month of the spring, March, is a frosty month in Marietta, Illinois, with an average temperature fluctuating between 34.3°F (1.3°C) and 49.6°F (9.8°C). As Marietta transitions into March, the average high-temperature shows a change, moving from an icy 36.3°F (2.4°C) in February to a frosty 49.6°F (9.8°C). Weather in March »
Weather in April
April in Marietta, Illinois, is a comfortable spring month, with an average temperature varying between 44.2°F (6.8°C) and 61.3°F (16.3°C). In Marietta, the average high-temperature in April rises, from a chilly 49.6°F (9.8°C) in March, to a refreshing 61.3°F (16.3°C). Weather in April »
Weather in May
May, the last month of the spring in Marietta, is an agreeable month, with an average temperature fluctuating between 55°F (12.8°C) and 72°F (22.2°C). Marietta's weather shows a temperature rise with the arrival of May, moving from a refreshing 61.3°F (16.3°C) in April to an agreeable 72°F (22.2°C). Weather in May »
Weather in June
The first month of the summer, June, is a warm month in Marietta, Illinois, with an average temperature ranging between min 63.7°F (17.6°C) and max 80.8°F (27.1°C). June introduces a marginal temperature uplift, with average high-temperatures adjusting from May's agreeable 72°F (22.2°C) to a moderately hot 80.8°F (27.1°C). Weather in June »
Weather in July
July, like June, in Marietta, Illinois, is another warm summer month, with an average temperature fluctuating between 82.8°F (28.2°C) and 65.8°F (18.8°C). July tends to be the warmest month, with temperatures averaging a daily high of 82.8°F (28.2°C) and a low of 65.8°F (18.8°C). In July, the average heat index is calculated to be a hot 91.4°F (33°C). Weather in July »
Weather in August
The last month of the summer, August, is another warm month in Marietta, Illinois, with an average temperature fluctuating between 82°F (27.8°C) and 63.7°F (17.6°C). August's beginning signals an average high-temperature of a still moderately hot 82°F (27.8°C), barely different from July's 82.8°F (28.2°C). Weather in August »
Weather in September
The first month of the autumn, September, is also a moderately hot month in Marietta, Illinois, with an average temperature fluctuating between 76.6°F (24.8°C) and 57.6°F (14.2°C). September's arrival signals a moderate reduction in the average high-temperature, easing from a moderately hot 82°F (27.8°C) in August to a still warm 76.6°F (24.8°C). Weather in September »
Weather in October
October, the same as September, is another comfortable autumn month in Marietta, Illinois, with an average temperature varying between 63°F (17.2°C) and 46.6°F (8.1°C). Marietta's weather changes with the onset of October, slightly falling from a warm 76.6°F (24.8°C) in September to an enjoyable 63°F (17.2°C). Weather in October »
Weather in November
The last month of the autumn, November, is another chilly month in Marietta, Illinois, with temperature in the range of an average high of 49.1°F (9.5°C) and an average low of 35.1°F (1.7°C). In November, the meteorological conditions alter, with the average high-temperature shifting from an enjoyable 63°F (17.2°C) in October to a frosty 49.1°F (9.5°C). Weather in November »
Weather in December
The first month of the winter, December, is also a wintry month in Marietta, Illinois, with temperature in the range of an average low of 26.4°F (-3.1°C) and an average high of 37°F (2.8°C). Marietta's December weather shows a moderate shift in high-temperatures, falling from November's chilly 49.1°F (9.5°C) to a cold 37°F (2.8°C). Weather in December »
Updated: Feb 12, 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 is the coldest time of year in Marietta?
January is the coldest month in Marietta, Illinois, exhibiting average temperatures of 31.5°F (-0.3°C) at the peak and 19.4°F (-7°C) at the base.
How many days does it rain in Marietta?
Throughout the year, in Marietta, Illinois, there are 131.7 rainfall days, and 22.48" (571mm) of precipitation is accumulated.
When does it snow in Marietta?
Months with snowfall in Marietta, Illinois, are January through April, October through December.
What is the snowiest month in Marietta?
The month with the most snowfall is January, when snow falls for 9.4 days and typically aggregates up to 3.35" (85mm) of snow.
How much does it snow in Marietta?
In Marietta, Illinois, during the entire year, snow falls for 27.4 days and aggregates up to 9.21" (234mm) of snow.
What is the month with the least sunshine in Marietta?
The month with the least sunshine in Marietta is January, with an average of 4.1h of sunshine.
When is the lowest UV index in Marietta?
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
When is Daylight Saving Time (DST) in Marietta?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Marietta, 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 in Marietta?
May is the month with the most rainfall in Marietta, Illinois. Rain falls for 16.7 days and accumulates 3.23" (82mm) of precipitation.
When it does not snow in Marietta?
May through September are months without snowfall.
When are the longest days in Marietta?
The month with the longest days is June, with an average of 15h and 0min of daylight.
What are the months with the most sunshine in Marietta?
June and July, with an average of 10.1h of sunshine, are months with the most sunshine.
When is the highest UV index in Marietta?
The months with the highest UV index in Marietta, Illinois, are June through August, with an average maximum UV index of 6.
What is the hottest time of year in Marietta?
The warmest period in Marietta, Illinois, tends to be July, when average temperatures fluctuate between a high of 82.8°F (28.2°C) and a low of 65.8°F (18.8°C).
What is the most humid month in Marietta?
The most humid month in Marietta is July, with an average relative humidity of 83%.
What is the least humid month in Marietta?
With an average relative humidity of 71%, October is the least humid month.
What is the driest month in Marietta?
December is the month with the least rainfall in Marietta, Illinois. Rain falls for 6.5 days and accumulates 0.94" (24mm) of precipitation.
What is the month with the shortest days in Marietta?
December has the shortest days of the year in Marietta, Illinois, with an average of 9h and 18min of daylight.
Average temperature
Marietta, IL
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (31.5°F).
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (19.4°F).
Average pressure
Marietta, IL
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Marietta, IL
- Average wind speed in January:
10.3mph - Average wind speed in February:
10.3mph - Average wind speed in March:
10.3mph - Average wind speed in April:
10.4mph - Average wind speed in May:
8.7mph - Average wind speed in June:
7.6mph
- Average wind speed in July:
6.5mph - Average wind speed in August:
6.5mph - Average wind speed in September:
7.5mph - Average wind speed in October:
9.2mph - Average wind speed in November:
9.9mph - Average wind speed in December:
9.8mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.5mph).
Average humidity
Marietta, IL
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Marietta, IL
- Average rainfall in January:
1.02" - Average rainfall in February:
1.1" - Average rainfall in March:
1.65" - Average rainfall in April:
2.6" - Average rainfall in May:
3.23" - Average rainfall in June:
2.68"
- Average rainfall in July:
2.17" - Average rainfall in August:
1.89" - Average rainfall in September:
2.09" - Average rainfall in October:
1.89" - Average rainfall in November:
1.22" - Average rainfall in December:
0.94"
The wettest month (with the highest rainfall) is May (3.23").
The driest month (with the least rainfall) is December (0.94").
Average rainfall days
Marietta, IL
- Average rainfall days in January:
4.8 days - Average rainfall days in February:
4.7 days - Average rainfall days in March:
11.9 days - Average rainfall days in April:
13.7 days - Average rainfall days in May:
16.7 days - Average rainfall days in June:
15.8 days
- Average rainfall days in July:
15.8 days - Average rainfall days in August:
13.2 days - Average rainfall days in September:
11 days - Average rainfall days in October:
10.5 days - Average rainfall days in November:
7.1 days - Average rainfall days in December:
6.5 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is February (4.7 days).
Average snowfall
Marietta, IL
The month with the highest snowfall is January (3.35").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Marietta, IL
- Average snowfall days in January:
9.4 days - Average snowfall days in February:
6.8 days - Average snowfall days in March:
3.3 days - Average snowfall days in April:
1 days - Average snowfall days in May:
0 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:
0.1 days - Average snowfall days in November:
1.8 days - Average snowfall days in December:
5 days
The month with the highest number of snowfall days is January (9.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Marietta, IL
- Average daylight in January:
9h and 4min - 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 3min - Average daylight in June:
15h and 0min
- Average daylight in July:
14h and 4min - Average daylight in August:
13h and 4min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 1min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in January:
4h and 1min - Average sunshine in February:
4h and 2min - Average sunshine in March:
6h and 3min - Average sunshine in April:
8h and 1min - Average sunshine in May:
9h and 0min - Average sunshine in June:
10h and 1min
- Average sunshine in July:
10h and 1min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 2min - Average sunshine in October:
5h and 4min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 3min
The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days
Marietta, IL
- Average sunshine days in January:
17.9 days - Average sunshine days in February:
17 days - Average sunshine days in March:
16.3 days - Average sunshine days in April:
14.6 days - Average sunshine days in May:
12.5 days - Average sunshine days in June:
11.1 days
- Average sunshine days in July:
11.7 days - Average sunshine days in August:
14.6 days - Average sunshine days in September:
17.1 days - Average sunshine days in October:
17.9 days - Average sunshine days in November:
20 days - Average sunshine days in December:
20.4 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.1 days).
Average UV index
Marietta, IL
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
Marietta, IL
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility
Marietta, 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).
Marietta, Illinois, USA
Weather forecast for your location
1. Click Locate me button
2. Allow the app to use your location
2. Allow the app to use your location