May weather forecast
Saint Peters, MO

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Weather in May

May presents an amalgamation of increased warmth and humidity in Saint Peters, Missouri. Marked increases in temperature and rising humidity levels characterize the advent of summer. This month stands out due to its peak temperature raising above 74.7°F (23.7°C) for the first time in the year. As daylight extends and sunshine becomes more prevalent, weather conditions become idyllic for outdoor pursuits. The weather patterns in May set the foundations for the hot summer weather that June carries forth.

Temperature

Saint Peters's weather in May presents a rise in the average high-temperature, moving from a refreshing 65.3°F (18.5°C) in April to a warm 74.7°F (23.7°C). During the month of May, the nighttime temperature falls to an average of 57°F (13.9°C).

Humidity

With an average relative humidity of 78%, May is the most humid month.

Rainfall

In May, the rain falls for 15.6 days. Throughout May, 2.44" (62mm) of precipitation is accumulated. In Saint Peters, during the entire year, the rain falls for 133.4 days and collects up to 20.98" (533mm) of precipitation.

Snowfall

April through October are months without snowfall.

Daylight

The average length of the day in May is 14h and 19min.
On the first day of the month, sunrise is at 6:03 am and sunset at 7:55 pm. On the last day of May, sunrise is at 5:39 am and sunset at 8:21 pm CDT.

Sunshine

In May, the average sunshine is 9.6h.

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: A maximum high UV index of 6 in May translates into the following recommendations:
Guard against overexposure. Protection from sun-induced harm is essential. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Updated: Aug 16, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in May?

In May, in Saint Peters, the average high-temperature is 74.7°F (23.7°C), and the average low-temperature is 57°F (13.9°C).

What is the most humid month?

May is the most humid month, with an average relative humidity of 78%.

What is the average humidity in May?

The average relative humidity in May is 78%.

How much does it rain in May?

In May, the rain falls for 15.6 days. Throughout May, 2.44" (62mm) of precipitation is accumulated.

When it does not snow?

April through October are months without snowfall.

What is the average length of the day in May?

In Saint Peters, the average day length in May is 14h and 19min.

What time are sunrise and sunset in May?

On the first day of May, sunrise is at 6:03 am and sunset at 7:55 pm. On the last day of the month, sunrise is at 5:39 am and sunset at 8:21 pm CDT.

How long on average sun shines in May?

In Saint Peters, the average sunshine duration in May is 9.6h.

What are the months with the highest UV index?

The months with the highest UV index are May through August, with an average maximum UV index of 6.

What is the UV index reading in May?

The average daily maximum UV index in May is 6. A UV Index reading of 6 to 7 represents a high health threat 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
Saint Peters, MO

Average temperature in May - Saint Peters, MO
  • Average high temperature in May: 74.7°F

The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in May: 57°F

The month with the highest average low temperature is July (68.4°F).
The coldest month (with the lowest average low temperature) is January (23.9°F).

Average pressure in May
Saint Peters, MO

Average pressure in May - Saint Peters, MO
  • Average pressure in May: 29.95"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in May
Saint Peters, MO

Average wind speed in May - Saint Peters, MO
  • Average wind speed in May: 7.1mph

The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).

Average humidity in May
Saint Peters, MO

Average humidity in May - Saint Peters, MO
  • Average humidity in May: 78%

The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (71%).

Average rainfall in May
Saint Peters, MO

Average rainfall in May - Saint Peters, MO
  • Average rainfall in May: 2.44"

The wettest month (with the highest rainfall) is April (2.48").
The driest month (with the least rainfall) is February (1.06").

Average rainfall days in May
Saint Peters, MO

Average rainfall days in May - Saint Peters, MO
  • Average rainfall days in May: 15.6 days

The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (6.7 days).

Average snowfall in May
Saint Peters, MO

Average snowfall in May - Saint Peters, MO
  • Average snowfall in May: 0"

The month with the highest snowfall is February (1.65").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in May
Saint Peters, MO

Average snowfall days in May - Saint Peters, MO
  • Average snowfall days in May: 0 days

The months with the highest number of snowfall days are January and February (5.8 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
Saint Peters, MO

Average daylight in May / Average sunshine in May - Saint Peters, MO
  • Average daylight in May: 14h and 2min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in May: 9h and 4min

The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

Average sunshine days in May
Saint Peters, MO

Average sunshine days in May - Saint Peters, MO
  • Average sunshine days in May: 13 days

The month with the most sunshine days is January (20.4 days).
The month with the least sunshine days is July (12.7 days).

Average UV index in May
Saint Peters, MO

Average UV index in May - Saint Peters, MO
  • Average UV index in May: 6

The months with the highest UV index are May, 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
Saint Peters, MO

Average cloud cover in May - Saint Peters, MO
  • Average cloud cover in May: 36

The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in May
Saint Peters, MO

Average visibility in May - Saint Peters, MO
  • 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).

Saint Peters, Missouri, USA

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