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January Weather in Saint Louis, United States

Last updated: June 24, 2025

In January, the average temperature in Saint Louis, United States hovers around -4°C (24°F), with extremes ranging from a chilling -26°C (-15°F) to a milder 14°C (58°F). Expect 55 mm (2.2 in) of precipitation over approximately 8 days, and be prepared for a high average humidity of 88%.

January Temperature in Saint Louis

In January in Saint Louis, the average temperature is -4°C (24°F). Maximum temperatures can reach 14°C (58°F), while the minimum can dip as low as -26°C (-15°F). Be prepared for a wide range of temperatures and pack accordingly for your trip.

January Weather in Saint Louis: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Saint Louis, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint Louis, January typically has an average temperature of -4°C (24°F), with highs reaching up to 14°C (58°F) and lows dropping to around -26°C (-15°F).
JanFebMarAprMayJunJulAugSepOctNovDec242535455869747164523730
Data source: Temperature data for Saint Louis generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

January Precipitation in Saint Louis

In Saint Louis in January, the precipitation amount is 55 mm (2.2 in) over the course of 8 days.

January Precipitation Trends in Saint Louis

The chart displays monthly precipitation patterns in Saint Louis, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Saint Louis, January typically receives around 55 mm (2.2 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec555958861151136781981205763
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
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January Humidity in Saint Louis

In Saint Louis in January, humidity is 88%. With an average temperature of -4°C (24°F), this humidity feels like an icy blanket enveloping you, making every breath feel crisp and biting, which can be quite challenging for traveling.

January Average Humidity in Saint Louis

This chart illustrates the average monthly humidity levels in Saint Louis, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Saint Louis is approximately 88%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%85%86%80%80%80%81%80%84%90%86%
Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Saint Louis

In Saint Louis in January, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Saint Louis, you can visit Hourly UV Index in Saint Louis.

Maximum UV Index Levels in Saint Louis for January

The chart shows the monthly maximum UV Index (UVI) for Saint Louis in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Saint Louis typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2458910997532
Data source: Saint Louis January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How January Weather in Saint Louis Compares to Other Months

Weather in Saint Louis varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Saint Louis, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Saint Louis, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-4°C (24°F)55 mm (2.2 inches)88%low
February Weather-4°C (25°F)59 mm (2.3 inches)87%moderate
March Weather2°C (35°F)58 mm (2.3 inches)85%moderate
April Weather7°C (46°F)86 mm (3.4 inches)86%very high
May Weather15°C (59°F)115 mm (4.5 inches)80%very high
June Weather20°C (69°F)113 mm (4.5 inches)80%very high
July Weather23°C (74°F)67 mm (2.7 inches)80%very high
August Weather22°C (71°F)81 mm (3.2 inches)80%very high
September Weather18°C (64°F)98 mm (3.9 inches)80%high
October Weather11°C (52°F)120 mm (4.7 inches)84%moderate
November Weather3°C (38°F)57 mm (2.2 inches)89%moderate
December Weather-1°C (31°F)63 mm (2.5 inches)86%low

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