April Weather in St. Louis, United States

Last updated: February 24, 2025

In April, St. Louis experiences a vibrant transition into spring, with temperatures soaring to a maximum of 30°C (87°F) during warm days while dipping to a minimum of -4°C (24°F) at night. The month boasts an average temperature of 13°C (55°F), setting a pleasant stage for outdoor activities. However, residents should prepare for a touch of moisture, as the city receives approximately 129 mm (5.1 inches) of rain over 11 days, contributing to a humidity level of 80%. This blend of warmth and occasional showers invigorates the landscape, heralding the beauty of blooming flowers and lush greenery.

April Temperature in St. Louis

In April, St. Louis begins its transition into warmer weather, leaving the chill of winter behind. With a minimum temperature of -4°C (24°F), the month marks a noticeable rise from the frigid depths of earlier months. Daytime highs can reach an inviting 30°C (87°F), showcasing spring's full bloom. The average temperature settles at a comfortable 13°C (55°F), creating a pleasant atmosphere for outdoor activities. As spring unfolds, residents can expect more sunshine and milder conditions, signaling the approach of summer while still holding onto the last remnants of cool weather from winter. Overall, April serves as a vibrant bridge to the increasingly warm months ahead.

April Weather in St. Louis: Daily Temperature Highs, Lows, and Averages

The chart illustrates April temperature patterns in St. Louis, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec323547556777807672594439
Data source: Temperature data for St. 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.

April Precipitation in St. Louis

April in St. Louis sees a notable consistency in precipitation, with 129 mm (5.1 in) of rainfall spread across 11 days. This volume is slightly less than the preceding month, March, which recorded 131 mm (5.2 in), yet it continues the trend of ample spring moisture that helps nurture the awakening landscape. As the city transitions into May, which typically brings even higher rainfall averages at 145 mm (5.7 in) over 14 days, April serves as an essential bridge, maintaining the rhythm of growth and rejuvenation. The rainfall during this time not only enhances the lushness of the region but also signals the onset of a vibrant spring season, characterized by its dynamic weather patterns.

April Precipitation Trends in St. Louis

The chart displays monthly precipitation patterns in St. Louis, with values for each month alongside April's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec768013112914510197130561057559
Data source: Precipitation data for April generated using information from the Copernicus Climate Change Service.
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April Humidity in St. Louis

In April, humidity levels in St. Louis remain stable, hovering around 80%, consistent with the previous months of February and March. This trend reflects a moderate transition as the city prepares for the rising humidity associated with the warmer months ahead. Interestingly, while January and November showcase higher humidity levels at 82% and 85% respectively, April's relatively balanced humidity suggests a more comfortable climate, making it an enjoyable spring month. As the year progresses towards May, we can expect a slight uptick, aligning with the city’s trend of increasing humidity leading into summer.

April Average Humidity in St. Louis

This chart illustrates the average monthly humidity levels in St. Louis, with April's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how April's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%80%82%83%81%80%76%76%85%86%
Data source: Humidity data for April generated using information from the Copernicus Climate Change Service.

April UV Index in St. Louis

As spring blossoms in St. Louis, the UV Index takes a noticeable leap in April, rising to a striking 9—an indicator of very high exposure that significantly reduces burn time to just 15 minutes. This increase from March's 6 emphasizes the need for vigilant sun protection as warmer days encourage more outdoor activities. With April marking the transition into peak UV months, residents should brace for even higher indices in May, reaching 10. The trend highlights a critical shift; as temperatures rise, so does the intensity of UV radiation. Remember to stay informed and protect your skin during these vibrant spring days by checking detailed forecasts at St. Louis UV Index.

Maximum UV Index Levels in St. Louis for April

The chart shows the monthly maximum UV Index (UVI) for St. Louis in April, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3569101110109643
Data source: St. Louis April 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.

April Sunshine in St. Louis

As April dawns in St. Louis, residents revel in a notable surge of sunshine hours, totaling an impressive 241 hours—a vibrant contrast to the 125 hours experienced in January. This upward trend continues from the early months of the year, as February and March also show significant increases, highlighting spring’s awakening. With the city preparing for the warmth of summer, April marks a pivotal moment where the sun begins to dominate the skies, paving the way for even more luminous months ahead. As the sunshine hours accumulate, spirits lift and outdoor activities flourish, solidifying April as a cherished month of renewal and vitality in the heart of the United States.

Monthly Sunshine Duration in St. Louis: April Highlighted

The April sunshine duration represents the total number of hours St. Louis experiences direct sunlight during the month of April, excluding cloudy or obstructed periods. This chart compares the sunshine duration of April with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec125h174h205h241h287h328h348h330h290h239h211h197h
Data source: St. Louis April Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in St. Louis During April

As spring awakens in St. Louis, the likelihood of sunny weather sees a promising uptick in April, climbing to 49%. This marks a noticeable increase from the 44% chance in March, indicating a trend of increasing sunshine as warmer days approach. Interestingly, while April offers a glimmer of hope for outdoor activities, it contrasts sharply with May's dip to 26%, reminding us that spring weather can be quite unpredictable. Moreover, as we move into the summer months, the chances of sunny skies continue to hover above 50%, highlighting a gradual transition towards a sunnier season. Thus, April serves as an exciting bridge, inviting St. Louis residents to embrace the essence of spring while keeping an eye on the evolving weather patterns ahead.

Percentage of Sunny Days in April in St. Louis

The chart illustrates the percentage of sunny days in St. Louis throughout the year, with April highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often St. Louis experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec30%30%44%49%26%41%51%47%64%39%53%47%
Data source: St. Louis April chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in St. Louis in April

As spring settles in, April brings a delightful increase in daylight to St. Louis, with the sun gracing the skies for an invigorating 13 hours. This significant jump from 11 hours in March highlights the transition toward longer days, a trend that continues into May, where daylight peaks at 14 hours. The gradual increase from January's fleeting 9 hours to the abundant light of April reflects the warming embrace of the season, with longer days paving the way for outdoor activities and blooming nature. As summer nears, St. Louisans can relish the growing sunshine, marking a vibrant contrast to the darker winter months.

Average Daylight Hours in St. Louis for April

The chart illustrates the variation in daylight duration in St. Louis throughout the year, with April highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 47m10h 45m11h 58m13h 14m14h 17m14h 48m14h 31m13h 35m12h 23m11h 8m10h 2m9h 29m
Data source: St. Louis daylight hours, calculated by summing the hours between sunrise and sunset for each day.

April Winds in St. Louis

In April, St. Louis experiences a gentle breeze with an average wind speed of 3.5 m/s (8 mph), slightly mellowing from the more dynamic gusts of March. This moderate wind pattern reflects a transition as the city warms up, remaining consistent with the spring season's gradually calming atmosphere. While April’s winds are a touch lower than those of the previous month, they still hold a refreshing quality, serving as a delightful precursor to the more tranquil summer months ahead. After April, the winds begin a gradual decline, with May showcasing a slight drop to 3.2 m/s, indicating a trend toward a laid-back seasonal pace. In summary, April's winds in St. Louis strike a perfect balance, encapsulating the essence of spring while hinting at the slower rhythms of summer just around the corner.

Average April Wind Speed in St. Louis

The chart displays monthly wind speed patterns in St. Louis, with values for each month shown alongside April's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how April's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.33.73.83.5 m/s3.22.82.12.43.03.53.43.6
Data source: St. Louis April wind data, generated using information from the Copernicus Climate Change Service.

How April Weather in St. Louis Compares to Other Months

The weather in St. Louis changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of April'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.

April's weather is marked by a significant warming trend compared to January, with temperatures ranging from a chilly minimum of -4°C (24°F) to a pleasant maximum of 30°C (87°F) and an average of 13°C (55°F). In contrast, January experiences much colder temperatures, with a minimum of -22°C (-7°F), an average of 0°C (32°F), and a maximum of only 19°C (67°F). While April brings more precipitation at 129 mm (5.1 in) over 11 days and higher humidity levels of 80%, January has less precipitation at 76 mm (3.0 in) over 8 days, coupled with a slightly higher humidity of 82%. For a detailed look at January weather, you can check out St. Louis weather in January.

When comparing the weather in April and February, the contrast is striking. April experiences a much milder temperature range, with lows at -4°C (24°F) and highs reaching up to 30°C (87°F), whereas February sees much colder temperatures, with minimums dropping to -19°C (-1°F) and a maximum of only 24°C (76°F). Precipitation is also more pronounced in April, with 129 mm (5.1 in) over 11 days, compared to February's 80 mm (3.2 in) over 10 days. Interestingly, both months share the same humidity level of 80%, but April’s warmer conditions make it feel quite different overall. For more information on February’s climate, you can visit St. Louis weather in February.

April generally experiences milder temperatures compared to March, with average highs reaching 30°C (87°F) as opposed to March's maximum of 27°C (81°F). While both months are characterized by similar humidity levels at 80%, April tends to be a bit wetter with 129 mm (5.1 in) of precipitation over 11 days, slightly less than March's 131 mm (5.2 in) over 12 days. The shift from the frigid minimum of -17°C (2°F) in March to a more temperate -4°C (24°F) in April marks a notable welcome to spring. For more detailed insights into the weather patterns, you can check out St. Louis weather in March.

In comparing the weather between April and May, April experiences a wider temperature range, with minimums dropping as low as -4°C (24°F) and maximums reaching up to 30°C (87°F). In contrast, May sees milder minimums at 4°C (40°F) and higher average temperatures, peaking at 34°C (94°F). Precipitation increases slightly from 129 mm (5.1 in) in April to 145 mm (5.7 in) in May, with May also experiencing more rainy days, totaling 14 compared to April's 11. Humidity levels remain quite similar, with April at 80% and May slightly higher at 82%. For a detailed overview of the conditions during this month, you can refer to St. Louis weather in May.

In comparing the weather between April and June, April tends to be noticeably cooler, with temperatures ranging from a minimum of -4°C (24°F) to a maximum of 30°C (87°F) and an average temperature of 13°C (55°F). April also experiences higher precipitation, with 129 mm (5.1 in) falling over 11 days and a humidity level of 80%. In contrast, June is much warmer, featuring minimum temperatures of 12°C (54°F), an average of 25°C (77°F), and maximums reaching 36°C (98°F). Although June has slightly less precipitation at 101 mm (4.0 in) over the same number of days, it has a marginally higher humidity of 83%. For more detailed insights, you can check St. Louis weather in June.

April and July present stark contrasts in weather conditions. In April, temperatures can dip as low as -4°C (24°F) at night, with an average of 13°C (55°F) and maximums reaching up to 30°C (87°F). The month experiences considerable precipitation, totaling 129 mm (5.1 in) over 11 days, and high humidity at around 80%. In contrast, July is significantly warmer, with nighttime temperatures starting at a milder 16°C (61°F), an average of 26°C (80°F), and highs soaring to 38°C (101°F). While July has less precipitation at 97 mm (3.8 in) over the same number of rainy days, the humidity slightly increases to 81%, making for a muggy atmosphere. For more insights on July's climate specifics, you can check out St. Louis weather in July.

April and August exhibit distinct weather characteristics, with April showcasing a wider temperature range that dips as low as -4°C (24°F) and occasionally peaks at 30°C (87°F). The average temperature in April is a mild 13°C (55°F), albeit with 129 mm (5.1 in) of precipitation across 11 days, contributing to a relatively humid environment with 80% humidity. In contrast, August enjoys warmer temperatures, with a minimum of 12°C (54°F), an average of 25°C (76°F), and a maximum reaching 35°C (96°F). Despite similar precipitation levels of 130 mm (5.1 in) over 11 days, August maintains the same humidity level of 80%. For more details on August’s climate specifics, you can visit St. Louis weather in August.

April and September present notable differences in weather patterns. In April, temperatures can range significantly from a chilly -4°C (24°F) at night to a warm 30°C (87°F) during the day, with an average of 13°C (55°F). This month also sees considerable precipitation, averaging 129 mm (5.1 in) over approximately 11 days, contributing to a high humidity level of 80%. In contrast, September enjoys milder temperatures, starting at a minimum of 7°C (45°F) and rising to a maximum of 35°C (95°F), with an average temperature of 22°C (73°F). Rainfall is less frequent in September, with only 56 mm (2.2 in) over 7 days, and a slightly lower humidity of 76%. For more detailed information, you can explore St. Louis weather in September.

April and October present a fascinating contrast in weather patterns. In April, temperatures can fluctuate significantly, ranging from a chilly -4°C (24°F) to a warm 30°C (87°F), with an average of 13°C (55°F). This month also sees around 129 mm (5.1 in) of precipitation spread over 11 days, accompanied by high humidity levels at 80%. In comparison, October has slightly milder conditions, with temperatures ranging from -4°C (26°F) to a warmer 34°C (93°F) and an average of 15°C (59°F). While it experiences slightly less precipitation at 105 mm (4.1 in) across the same number of days, humidity dips to 76%. For a detailed look at what to expect during this time, check out St. Louis weather in October.

April and November present distinctly different weather patterns. April typically experiences a wider temperature range, with minimums dropping to -4°C (24°F) and maximums reaching up to 30°C (87°F), resulting in an average temperature of 13°C (55°F). In contrast, November sees cooler conditions, with a minimum temperature of -13°C (9°F) and a maximum of 25°C (78°F), leading to a lower average of 7°C (44°F). While April is characterized by higher precipitation levels (129 mm or 5.1 in) over 11 days and slightly lower humidity (80%), November brings less rainfall (75 mm or 2.9 in) over 9 days, accompanied by higher humidity at 85%. For more detailed information, you can visit St. Louis weather in November.

April and December present stark contrasts in weather patterns. In April, temperatures range from a chilly minimum of -4°C (24°F) to a warm maximum of 30°C (87°F), averaging around 13°C (55°F). With 129 mm (5.1 in) of precipitation over approximately 11 days, the month is often marked by rain and a humidity level of 80%. Conversely, December experiences much colder temperatures, with a minimum of -18°C (0°F) and a maximum of 22°C (71°F), averaging just 4°C (39°F). Precipitation is lighter, totaling 59 mm (2.3 in) across about 7 days, and humidity increases slightly to 86%. For those interested in more about the winter climate, check out St. Louis weather in December.

Compare St. Louis's Climate with Cities Worldwide

Conclusion: What to Expect From April Weather in St. Louis

As April rolls in, St. Louis experiences a notable transition from the brisk chill of winter to the warmer embrace of spring. This month stands out with average temperatures that are significantly milder, providing a refreshing respite from the colder months, but also presents the potential for sudden fluctuations, with daytime highs and nighttime lows varying greatly. April's increased humidity and precipitation, manifested through several rainy days, infuse the atmosphere with a vibrant freshness, making it a crucial month for blooming gardens and lush landscapes. If you're curious about how April compares to the year-round weather patterns, check out St. Louis Climate.