St. Louis
Missouri, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
St. Louis, MO

A beautiful twilight view of the Gateway Arch in St. Louis, Missouri, with a distant view of the city buildings mirrored in the waterfront
A beautiful twilight view of the Gateway Arch in St. Louis, Missouri, with a distant view of the city buildings mirrored in the waterfront
The first month of the winter, Diciembre, is still a cold month in St. Louis, Missouri, with average temperature fluctuating between 27°F (-2.8°C) and 42.4°F (5.8°C).

Temperature

In Diciembre, the average high-temperature in St. Louis drops, from a mild 55.6°F (13.1°C) in Noviembre, to a cold 42.4°F (5.8°C). In Diciembre, in St. Louis, the average low-temperature is 27°F (-2.8°C).

Humidity

Diciembre is the most humid month in St. Louis, with an average relative humidity of 75.8%.

Rainfall

In St. Louis, it is raining for 9.4 days, with typically 2.84" (72.1mm) of accumulated precipitation. Throughout the year, in St. Louis, Missouri, there are 112.6 rainfall days, and 40.96" (1040.3mm) of precipitation is accumulated.

Snowfall

Enero through Abril, Noviembre and Diciembre are months with snowfall in St. Louis. In Diciembre, in St. Louis, it is snowing for 3.7 days. Throughout Diciembre, 4.4" (111.8mm) of snow is accumulated. Throughout the year, in St. Louis, there are 14.5 snowfall days, and 17.7" (449.6mm) of snow is accumulated.

Daylight

With an average of 9.5h of daylight, Diciembre has the shortest days of the year in St. Louis.

Sunshine

Diciembre has the least sunshine of the year in St. Louis, with an average of 4.2h of sunshine.

UV index

Enero and Diciembre, with an average maximum UV index of 2, are months with the lowest UV index in St. Louis. A UV Index estimate of 2, and below, represents a low health risk from the exposure to the Sun's UV radiation for ordinary individuals.
Note: In Diciembre, the average maximum UV index of 2 translate into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. 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. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in Diciembre in St. Louis?

The average high-temperature, in Diciembre, is 42.4°F (5.8°C), while the average low-temperature is 27°F (-2.8°C).

What is the most humid month in St. Louis?

The most humid month in St. Louis, Missouri, is Diciembre, with an average relative humidity of 75.8%.

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

In St. Louis, Missouri, the average relative humidity in Diciembre is 75.8%.

How many days does it rain in Diciembre in St. Louis?

In St. Louis, Missouri, in Diciembre, it is raining for 9.4 days, with typically 2.84" (72.1mm) of accumulated precipitation.

How much does it snow in St. Louis in Diciembre?

In St. Louis, in Diciembre, during 3.7 snowfall days, 4.4" (111.8mm) of snow is typically accumulated.

What is the month with the shortest days in St. Louis?

Diciembre has the shortest days of the year, with an average of 9.5h of daylight.

How many hours of daylight does St. Louis have in Diciembre?

The average length of the day in Diciembre is 9.5h.

What is the month with the least sunshine in St. Louis?

Diciembre has the least sunshine of the year, with an average of 4.2h of sunshine.

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

In Diciembre, the average sunshine in St. Louis, Missouri, is 4.2h.

What are the months with the lowest UV index in St. Louis?

Months with the lowest UV index in St. Louis, Missouri, are Enero and Diciembre, with an average maximum UV index of 2.

How high is the UV index in Diciembre in St. Louis?

In St. Louis, Missouri, the average daily maximum UV index in Diciembre is 2. A UV Index estimate of 2, and below, represents a low health threat from the exposure to the Sun's UV rays.
Average temperature in December - St. Louis, MO
  • Average high temperature in December: 42.5°F

The warmest month (with the highest average high temperature) is July (89.1°F).
The month with the lowest average high temperature is January (39.9°F).

  • Average low temperature in December: 26.9°F

The month with the highest average low temperature is July (71°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).

Average humidity in December - St. Louis, MO
  • Average humidity in December: 75.8%

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

Average rainfall in December - St. Louis, MO
  • Average rainfall in December: 2.8"

The wettest month (with the highest rainfall) is May (4.7").
The driest month (with the lowest rainfall) is February (2.2").

Average rainfall days in December - St. Louis, MO
  • Average rainfall days in December: 9.4 days

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

Average snowfall in December - St. Louis, MO
  • Average snowfall in December: 4.4"

The month with the highest snowfall is January (5.6").
Months with the lowest snowfall are May, June, July, August, September and October (0").

Average snowfall days in December - St. Louis, MO
  • Average snowfall days in December: 3.7 days

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

Average daylight in December / Average sunshine in December - St. Louis, MO
  • Average daylight in December: 9.5h

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

  • Average sunshine in December: 4.2h

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

Average UV index in December - St. Louis, MO
  • Average UV index in December: 2

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).