May weather forecast and climate
St. Louis, MO

A beautiful twilight over the Gateway Arch in St. Louis, Missouri
A beautiful twilight over the Gateway Arch in St. Louis, Missouri

Weather in May

May, the last month of the spring, in St. Louis, is a warm month, with average temperature varying between 76.3°F (24.6°C) and 57.2°F (14°C).

Temperature

In May, the average high-temperature in St. Louis slightly increases, from an enjoyable 67.5°F (19.7°C) in April, to a warm 76.3°F (24.6°C). In St. Louis, in May, the average low-temperature is 57.2°F (14°C).

Humidity

The average relative humidity in St. Louis, Missouri, is 66.5%.

Rainfall

May is the month with the most rainfall in St. Louis. Rain falls for 11.9 days and accumulates 4.72" (119.9mm) of precipitation.

Snowfall

In St. Louis snow does not fall through October.

Daylight

In May, the average length of the day in St. Louis, Missouri, is 14.3h.

Sunshine

In May, the average sunshine in St. Louis is 8.6h.

UV index

In St. Louis, the average daily maximum UV index in May is 8. A UV Index value of 8 to 10 symbolizes a very high health risk from the exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 8 transform into the following instructions:
Take extra precautions. Protection against sun damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the average humidity in May in St. Louis?

In St. Louis, the average relative humidity in May is 66.5%.

What is the wettest month in St. Louis?

The month with the most rainfall in St. Louis is May when the rain falls for 11.9 days and typically aggregates up to 4.72" (119.9mm) of precipitation.

How much does it rain in St. Louis in May?

In May, in St. Louis, Missouri, the rain falls for 11.9 days. Throughout May, 4.72" (119.9mm) of precipitation is accumulated.

When it does not snow in St. Louis?

In St. Louis, Missouri, snow does not fall in May through October.

Does it snow in St. Louis in May?

In May, in St. Louis, Missouri, it doesn't snow. April is the latest month when it typically snows.

What is the average length of the day in May in St. Louis?

The average length of the day in May is 14.3h.

How many hours of sunshine does St. Louis have in May?

In May, the average sunshine in St. Louis is 8.6h.

What is the UV index reading in May in St. Louis?

The average daily maximum UV index in May is 8. A UV Index of 8 to 10 symbolizes a very high hazard to health from the exposure to the Sun's UV rays.

Average temperature in May
St. Louis, MO

Average temperature in May - St. Louis, MO
  • Average high temperature in May: 24.6°C

The warmest month (with the highest average high temperature) is July (31.7°C).
The month with the lowest average high temperature is January (4.4°C).

  • Average low temperature in May: 14°C

The month with the highest average low temperature is July (21.7°C).
The coldest month (with the lowest average low temperature) is January (-4.6°C).

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Average humidity in May
St. Louis, MO

Average humidity in May - St. Louis, MO
  • Average humidity in May: 66.5%

The month with the highest relative humidity is December (75.8%).
The month with the lowest relative humidity is April (63.5%).

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Average rainfall in May
St. Louis, MO

Average rainfall in May - St. Louis, MO
  • Average rainfall in May: 119.9mm

The wettest month (with the highest rainfall) is May (119.9mm).
The driest month (with the least rainfall) is February (56.9mm).

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Average rainfall days in May
St. Louis, MO

Average rainfall days in May - St. Louis, MO
  • Average rainfall days in May: 11.9 days

The month with the highest number of rainy days is May (11.9 days).
The month with the least rainy days is September (7.4 days).

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Average snowfall in May
St. Louis, MO

Average snowfall in May - St. Louis, MO
  • Average snowfall in May: 0mm

The month with the highest snowfall is January (142.2mm).
Months with the least snowfall are May, June, July, August, September and October (0mm).

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Average snowfall days in May
St. Louis, MO

Average snowfall days in May - St. Louis, MO
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (4.7 days).
Months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in May /
Average sunshine in May
St. Louis, MO

Average daylight in May / Average sunshine in May - St. Louis, MO
  • Average daylight in May: 14.3h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in May: 8.6h

The month with the most sunshine is July (Average sunshine: 10h).
The month with the least sunshine is December (Average sunshine: 4.2h).

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Average UV index in May
St. Louis, MO

Average UV index in May - St. Louis, MO
  • Average UV index in May: 8

Months with the highest UV index are June, July and August (UV index 9).
Months with the lowest UV index are January and December (UV index 2).

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