May weather forecast
Marietta, IL

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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).

Temperature

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). During the nights in May, Marietta experiences a consistent average temperature of 55°F (12.8°C).

Humidity

The average relative humidity in May in Marietta is 78%.

Rainfall

The month with the most rainfall is May, when the rain falls for 16.7 days and typically aggregates up to 3.23" (82mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in May is 14h and 27min.
On the first day of the month, sunrise is at 5:59 am and sunset at 7:57 pm. On the last day of May, in Marietta, sunrise is at 5:33 am and sunset at 8:25 pm CDT.

Sunshine

In May, the average sunshine is 9h.

UV index

In May, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: In May, an average UV index of 5 transforms into the following instructions:
Undertake precautions - It is suggested to shield oneself from sunburn. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Marietta in May?

The high-temperature, in May, in Marietta, is 72°F (22.2°C), while the low-temperature averages to 55°F (12.8°C).

What is the average humidity in May in Marietta?

In Marietta, Illinois, the average relative humidity in May is 78%.

What is the wettest month in Marietta?

May is the month with the most rainfall. Rain falls for 16.7 days and accumulates 3.23" (82mm) of precipitation.

How many days does it rain in May in Marietta?

In Marietta, during May, the rain falls for 16.7 days and regularly aggregates up to 3.23" (82mm) of precipitation.

When it does not snow in Marietta?

May through September are months without snowfall in Marietta.

Does it snow in Marietta in May?

In May, in Marietta, Illinois, it doesn't snow. April is the latest month when it typically snows.

What is the average length of the day in May in Marietta?

In Marietta, Illinois, the average day length in May is 14h and 27min.

When are sunrise and sunset in May in Marietta?

On the first day of May in Marietta, Illinois, sunrise is at 5:59 am and sunset at 7:57 pm. On the last day of the month, sunrise is at 5:33 am and sunset at 8:25 pm CDT.

How long on average sun shines in May in Marietta?

The average sunshine duration in May is 9h.

What is the UV index intensity in May in Marietta?

In May, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Marietta, IL

Average temperature in May - Marietta, IL
  • Average high temperature in May: 72°F

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).

  • Average low temperature in May: 55°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 in May
Marietta, IL

Average pressure in May - Marietta, IL
  • Average pressure in May: 29.95"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 in May
Marietta, IL

Average wind speed in May - Marietta, IL
  • Average wind speed in May: 8.7mph

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 in May
Marietta, IL

Average humidity in May - Marietta, IL
  • Average humidity in May: 78%

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).

Average rainfall in May
Marietta, IL

Average rainfall in May - Marietta, IL
  • Average rainfall in May: 3.23"

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 in May
Marietta, IL

Average rainfall days in May - Marietta, IL
  • Average rainfall days in May: 16.7 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 in May
Marietta, IL

Average snowfall in May - Marietta, IL
  • Average snowfall in May: 0"

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 in May
Marietta, IL

Average snowfall days in May - Marietta, IL
  • Average snowfall days in May: 0 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 in May /
Average sunshine in May
Marietta, IL

Average daylight in May / Average sunshine in May - Marietta, IL
  • Average daylight in May: 14h and 3min

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 May: 9h and 0min

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 in May
Marietta, IL

Average sunshine days in May - Marietta, IL
  • Average sunshine days in May: 12.5 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 in May
Marietta, IL

Average UV index in May - Marietta, IL
  • Average UV index in May: 5

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 in May
Marietta, IL

Average cloud cover in May - Marietta, IL
  • Average cloud cover in May: 40

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 in May
Marietta, IL

Average visibility in May - Marietta, IL
  • Average visibility in May: 6mi

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

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