January 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
January, the same as December, is a wintry winter month in St. Louis, with average temperature ranging between min 23.7°F (-4.6°C) and max 39.9°F (4.4°C).

Temperature

The coldest month in St. Louis, Missouri, is January, with an average high-temperature of 39.9°F (4.4°C) and an average low-temperature of 23.7°F (-4.6°C).

Humidity

In St. Louis, the average relative humidity is 73%.

Rainfall

In St. Louis, in January, during 8.9 rainfall days, 2.4" (61mm) of precipitation is typically accumulated. In St. Louis, during the entire year, the rain falls for 112.6 days and collects up to 40.96" (1040.3mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall in St. Louis. January is the month with the most snowfall in St. Louis. Snow falls for 4.7 days and accumulates 5.6" (142.2mm) of snow.

Daylight

The average length of the day in January in St. Louis, Missouri, is 9.8h.

Sunshine

In St. Louis, the average sunshine in January is 5.2h.

UV index

January and December, with an average maximum UV index of 2, are months with the lowest UV index in St. Louis, Missouri. A UV Index of 2, and less, symbolizes a low health risk from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: In January, the average maximum UV index of 2 translate into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the coldest month in St. Louis?

With an average high-temperature of 39.9°F (4.4°C) and an average low-temperature of 23.7°F (-4.6°C), January is the coldest month in St. Louis, Missouri.

What is the temperature in January in St. Louis?

In St. Louis, Missouri, in January, the average high-temperature is 39.9°F (4.4°C), and the average low-temperature is 23.7°F (-4.6°C).

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

The average relative humidity in January in St. Louis, Missouri, is 73%.

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

In St. Louis, in January, it is raining for 8.9 days, with typically 2.4" (61mm) of accumulated precipitation.

How many days does it snow in January in St. Louis?

In St. Louis, Missouri, during January, snow falls for 4.7 days and regularly aggregates up to 5.6" (142.2mm) of snow.

When does it snow the most in St. Louis?

January is the month with the most snowfall in St. Louis. Snow falls for 4.7 days and accumulates 5.6" (142.2mm) of snow.

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

The average length of the day in January in St. Louis, Missouri, is 9.8h.

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

The average sunshine in January in St. Louis is 5.2h.

When is the lowest UV index in St. Louis?

Months with the lowest UV index are January and December, with an average maximum UV index of 2.

What is the UV index intensity in January in St. Louis?

In St. Louis, Missouri, the average daily maximum UV index in January is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from unprotected exposure to the UV radiation.
Average temperature in January - St. Louis, MO
  • Average high temperature in January: 4.4°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 January: -4.6°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).

Average humidity in January - St. Louis, MO
  • Average humidity in January: 73%

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 January - St. Louis, MO
  • Average rainfall in January: 61mm

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

Average rainfall days in January - St. Louis, MO
  • Average rainfall days in January: 8.9 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).

Average snowfall in January - St. Louis, MO
  • Average snowfall in January: 142.2mm

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

Average snowfall days in January - St. Louis, MO
  • Average snowfall days in January: 4.7 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).

Average daylight in January / Average sunshine in January - St. Louis, MO
  • Average daylight in January: 9.8h

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 January: 5.2h

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

Average UV index in January - St. Louis, MO
  • Average UV index in January: 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).