Last updated: February 24, 2025
December in St. Louis showcases a dynamic range of temperatures, with daily highs reaching a pleasant 22°C (71°F) while average lows dip to a chilly -18°C (0°F). As winter settles in, the month experiences an average temperature of 4°C (39°F). Rain and snow contribute to a total precipitation of 59 mm (2.3 in), spread across 7 days, resulting in a humidity level of 86% that adds to the crisp atmosphere. This blend of colder conditions and occasional precipitation encapsulates the essence of St. Louis during the festive month of December, offering a unique winter experience for residents and visitors alike.
In December, St. Louis transitions into winter, bringing a notable dip in temperatures. The month starts with a minimum of -18°C (0°F), setting the stage for chilly days ahead. As the month progresses, the average temperature hovers around 4°C (39°F), providing a stark contrast to the milder conditions of autumn. Daytime highs reach a comfortable 22°C (71°F), but the overall trend indicates a significant chill that marks the approach of colder months. This temperature pattern reflects the city's seasonal shift, where residents embrace the festive spirit despite the biting cold.
In December, St. Louis experiences a dip in precipitation, averaging 59 mm (2.3 inches) over about 7 days of rain. This marks a notable decrease from the wetter spring months, where levels peaked, particularly in March and May. As the year draws to a close, December's precipitation reflects a transitional phase, with fewer intense rain events compared to earlier months like April and August, which see more significant rainfall. The dry finish to the year sharpens the contrast between the heavy rains of spring and the more moderate conditions experienced in late fall, setting the stage for a typically brisk winter ahead.
December in St. Louis sees a notable uptick in humidity, settling at 86%, which marks it as one of the more humid months of the year. This rise follows November's chilly embrace of 85%, signaling the onset of winter when air moisture begins to accumulate. As we look back through the months, a trend emerges: humidity levels are consistently high from late fall to early winter, with January starting off at 82%. The overall consistency in humidity—hovering around 80% to 86% during these months—highlights a regional characteristic of St. Louis' climate, where the dampness can make the colder temperatures feel even more biting. As the year wraps up, December's humidity not only accentuates the cold but also prefaces the relatively damp winter ahead.
In St. Louis, December brings a return to a moderate UV Index of 3, mirroring the exposure levels seen in both January and November. This trend indicates that while the sun’s intensity is decreasing as winter sets in, it remains essential to be mindful of sun protection, especially during midday hours, with a burn time of 30 minutes. The previous months featured a notable peak in UV exposure during the summer, where indices soared to extreme levels in June. Following that, there was a gradual decline as autumn progressed, culminating in the now familiar winter UV Index pattern. This recurring seasonal fluctuation underscores the need for vigilance regarding sun safety year-round. For more insights, check out the detailed St. Louis UV Index.
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As December ushers in the close of the year, St. Louis enjoys an average of 197 hours of sunshine, a modest transition from the vibrant summer months. While December's sunlight hours are comfortably above the winter low of 125 hours in January, they reflect a gentle decline from the radiant peak of 348 hours in July. This month signals a notable shift as the city prepares for winter, with sunlight beginning to recede after its dazzling spring and summer displays. The gradual decrease in sunlight mirrors the seasonal rhythm, yet St. Louis still offers a respectable amount of brightness, making December a time for embracing the glowing charm of a city dressed for the holidays.
In St. Louis, December brings a moderate 47% chance of sunny weather, suggesting that while overcast days may dominate, there are still opportunities for clear skies. This percentage aligns closely with the earlier winter months, as both January and February linger at 30%. Interestingly, sunny days tend to peak in the fall, with September revealing the highest likelihood at 64%. As we transition into December, it's evident that while the sun may not shine as reliably as in summer months—like July, which boasts a 51% chance—there remains a consistent possibility of enjoying a bright afternoon amidst the winter chill. Overall, December reflects a transitional phase in St. Louis’ climate, where cold and sun can coexist, offering both chances for outdoor activities and cozy indoor days.
As the year draws to a close, December in St. Louis transitions into its shortest days, with daylight lasting around 9 hours. This marks a decline from the longer days of summer, where daylight peaked at a luxurious 14 hours in June, July, and August. Following this peak, the gradual decrease in daylight becomes evident as the months progress, with November offering only 10 hours before December ushers in the winter solstice. The trend showcases a natural ebb and flow of daylight throughout the year, highlighting St. Louis's seasonal shifts as residents embrace the cozy, darker days of winter, perfectly suited for festive gatherings and indoor activities.
As December settles in St. Louis, the average wind speed gently hovers around 3.6 m/s (8 mph), making it one of the calmer months of the year. Interestingly, this slight uptick from November's 3.4 m/s showcases a trend of increasingly brisk winds as winter approaches. Unlike the summer months, where winds are at their lowest (peaking at just 2.1 m/s in July), December reflects a transition back to more moderate wind speeds, resembling the values seen in earlier months like March and April. This subtle shift not only adds a crisp edge to the holiday atmosphere but also hints at the seasonal changes that come with the arrival of colder weather.
The weather in St. Louis changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of December's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in St. Louis and find detailed weather information for every month.
December and January exhibit notable differences in weather patterns. In December, temperatures range from a minimum of -18°C (0°F) to a maximum of 22°C (71°F), with an average temperature of 4°C (39°F). This month experiences 59 mm (2.3 in) of precipitation over about 7 days, alongside a relatively high humidity level of 86%. In contrast, January tends to be colder, with temperatures dropping to a minimum of -22°C (-7°F) and an average temperature of 0°C (32°F), reaching a maximum of 19°C (67°F). Additionally, January sees increased precipitation at 76 mm (3.0 in) over 8 days, though humidity is slightly lower at 82%. For more details about the weather in this month, you can check St. Louis weather in January.
December and February both feature cold temperatures, but there are noticeable differences in their weather patterns. In December, temperatures range from a minimum of -18°C (0°F) to a maximum of 22°C (71°F), with an average of 4°C (39°F) and higher humidity at 86%. In contrast, February is slightly colder with a minimum of -19°C (-1°F) and a lower average of 2°C (35°F), though it can reach up to 24°C (76°F). February also experiences more precipitation, totaling 80 mm (3.2 in) over 10 days compared to December's 59 mm (2.3 in) over 7 days. For more details on February weather, visit St. Louis weather in February.
In December, the weather is characterized by colder temperatures, ranging from a minimum of -18°C (0°F) to a maximum of 22°C (71°F), with an average of 4°C (39°F). The month sees about 59 mm (2.3 in) of precipitation over approximately 7 days, and the humidity is relatively high at 86%. In contrast, March experiences slightly milder temperatures, with a minimum of -17°C (2°F) and a maximum of 27°C (81°F), averaging around 8°C (47°F). However, March is wetter, with 131 mm (5.2 in) of precipitation spread over 12 days, while humidity levels drop slightly to 80%. For more detailed weather insights, check out St. Louis weather in March.
In December, temperatures can plummet to a chilling minimum of -18°C (0°F), with an average high of around 4°C (39°F), while precipitation is relatively low at 59 mm (2.3 in) over about 7 days, contributing to a high humidity level of 86%. In contrast, April brings a more moderate climate with temperatures ranging from a minimum of -4°C (24°F) to a pleasant maximum of 30°C (87°F) and an average of 13°C (55°F). However, it also sees increased rainfall, with precipitation totaling 129 mm (5.1 in) across approximately 11 days, coupled with a slightly lower humidity level of 80%. For a more detailed look at the weather in April, you can visit St. Louis weather in April.
In December, temperatures can be quite chilly, with minimums dropping to -18°C (0°F) and an average of 4°C (39°F), while highs peak at a mild 22°C (71°F). The month sees around 59 mm (2.3 in) of precipitation over approximately 7 days, accompanied by high humidity at 86%. In contrast, May experiences a significant warming trend, with minimum temperatures starting at 4°C (40°F) and rising to an average of 20°C (68°F), and maximums reaching 34°C (94°F). Precipitation increases notably to 145 mm (5.7 in) over 14 days, though humidity remains relatively lower at 82%. For a detailed breakdown of May weather, check St. Louis weather in May.
December and June showcase contrasting weather patterns. In December, temperatures can plummet to a minimum of -18°C (0°F), with an average temperature of about 4°C (39°F) and occasional highs reaching 22°C (71°F). The month experiences around 59 mm (2.3 in) of precipitation over seven days, accompanied by high humidity levels at 86%. In stark contrast, June offers a much warmer climate with minimum temperatures at 12°C (54°F) and average highs around 25°C (77°F), peaking at 36°C (98°F). This summer month sees increased rainfall, totaling 101 mm (4.0 in) over eleven rainy days, while humidity is slightly lower at 83%. For more detailed insights, you can check St. Louis weather in June.
December and July present stark contrasts in weather. In December, temperatures can dip as low as -18°C (0°F), with an average of 4°C (39°F), while highs reach a pleasant 22°C (71°F). The month sees around 59 mm (2.3 in) of precipitation over approximately 7 days, accompanied by high humidity at 86%. In contrast, July boasts much warmer conditions, with minimum temperatures around 16°C (61°F), an average of 26°C (80°F), and maximums soaring to 38°C (101°F). Precipitation increases to 97 mm (3.8 in) across about 11 days, but humidity remains slightly lower at 81%. For a more detailed look at July weather, check out St. Louis weather in July.
December weather contrasts sharply with that of August. In December, temperatures can plummet to a minimum of -18°C (0°F) and average around 4°C (39°F), while peaking at 22°C (71°F). This month experiences higher humidity levels at 86% and relatively low precipitation at 59 mm (2.3 in) over about 7 days. In contrast, August is much warmer, with minimum temperatures of 12°C (54°F) and averages reaching up to 25°C (76°F), maxing out at 35°C (96°F). August sees greater precipitation at 130 mm (5.1 in) across approximately 11 days, but lower humidity at 80%. For more details, visit St. Louis weather in August.
December weather contrasts sharply with September, showcasing a significant drop in temperatures. In December, minimum temperatures can plummet to -18°C (0°F), while average highs reach only 22°C (71°F), compared to September's more comfortable range, where minimums start at 7°C (45°F) and can peak at a much warmer 35°C (95°F). Precipitation levels are similar in both months, with December receiving 59 mm (2.3 in) and September slightly less at 56 mm (2.2 in), with 7 days of rain noted in each month. Humidity is higher in December at 86%, while September's humidity stands at a more moderate 76%. For more details on September weather, see St. Louis weather in September.
In comparing the weather of December and October, we see significant differences in temperature and precipitation. December experiences colder temperatures, with a minimum of -18°C (0°F) and an average of 4°C (39°F), while October boasts much milder conditions, featuring a minimum of -4°C (26°F) and an average of 15°C (59°F). Additionally, October sees higher maximum temperatures, reaching up to 34°C (93°F), compared to December's maximum of 22°C (71°F). Precipitation is also more pronounced in October, with 105 mm (4.1 in) over 11 days, contrasting with December's 59 mm (2.3 in) over 7 days. The humidity remains higher in December at 86%, compared to October's 76%. For more detailed information, check out St. Louis weather in October.
In December, temperatures range from a minimum of -18°C (0°F) to a maximum of 22°C (71°F), with an average of 4°C (39°F), while November exhibits slightly milder conditions with a minimum of -13°C (9°F) and a maximum of 25°C (78°F), averaging at 7°C (44°F). Precipitation in December totals 59 mm (2.3 in) over 7 days, compared to November's 75 mm (2.9 in) over 9 days. Humidity levels remain comparable, with December at 86% and November slightly lower at 85%. For more detailed insights into November's conditions, you can explore St. Louis weather in November.
December in St. Louis marks a distinct shift in weather, characterized by a notable drop in temperatures and a significant increase in humidity. With the coldest days bringing frigid lows contrasting sharply against occasional mild peaks, this month stands apart from the milder fall months. Precipitation, though relatively sparse, still graces the city several times, adding to the crisp atmosphere. As the air turns chillier and the festive season unfolds, St. Louis embraces the wintry charm that December uniquely offers. For a deeper understanding of how St. Louis weather evolves throughout the year, visit St. Louis Climate.