April weather forecast
St. Louis, MO

April in St. Louis signifies the full-fledged arrival of spring. A significant improvement in weather conditions becomes evident with the mean temperature increasing substantially. The temperature ranges from 47.2°F (8.4°C), warming the day considerably. April carries an increased likelihood of precipitation, bringing an average of more than 11 rainfall days. The citizens anticipate an enhancing panorama of spring vistas under increasing daylight hours.

Temperature

As St. Louis transitions into April, the average high-temperature shows a change, moving from a mild 55.9°F (13.3°C) in March to an enjoyable 67.5°F (19.7°C). The nighttime temperature in St. Louis dips to a chilly 47.1°F (8.4°C) on average during April.

Humidity

The least humid month in St. Louis is April, with an average relative humidity of 63.5%.

Rainfall

In St. Louis, during April, the rain falls for 11.3 days and regularly aggregates up to 3.7" (94mm) of precipitation. In St. Louis, during the entire year, the rain falls for 112.6 days and collects up to 40.94" (1040mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall in St. Louis. April is the last month it regularly snows in St. Louis. During 0.3 snowfall days, in April, St. Louis aggregates 0.39" (10mm) of snow. Throughout the year, in St. Louis, there are 14.5 snowfall days, and 17.72" (450mm) of snow is accumulated.

Daylight

The average length of the day in April in St. Louis is 13h and 14min.
On the first day of April in St. Louis, sunrise is at 6:44 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:03 am and sunset at 7:52 pm CDT.

Sunshine

The average sunshine in April in St. Louis is 7.5h.

UV index

The average daily maximum UV index in April in St. Louis is 7. A UV Index reading of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for average individuals.
Note: A typical high UV index of 7 in April suggests the following recommendations:
Act on precautions and pay attention to sun safety recommendations. Avoidance of sunburn is obligatory. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is at its strongest, and remember that parasols or canopies do not offer full protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.