Weather in May
Temperature
A minor escalation in the average high-temperature is seen in St. Louis with the onset of May, moving from a comfortable 67.5°F (19.7°C) in April to a moderately hot 76.3°F (24.6°C). During May, the nighttime temperature in St. Louis averages of 57.2°F (14°C).Humidity
In May, the average relative humidity in St. Louis is 66.5%.Rainfall
May is the month with the most rainfall in St. Louis. Rain falls for 11.9 days and accumulates 4.72" (120mm) of precipitation.Snowfall
In St. Louis, snow does not fall in May through October.Daylight
In St. Louis, the average length of the day in May is 14h and 17min.On the first day of May in St. Louis, sunrise is at 6:02 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 5:38 am and sunset at 8:19 pm CDT.
Sunshine
In St. Louis, the average sunshine in May is 8.6h.UV index
In May, the average daily maximum UV index in St. Louis is 8. A UV Index estimate of 8 to 10 represents a very high health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The average daily UV index of 8 in May transforms into the following instructions:
It is crucial to take precautions; skin and eyes can get damaged if left unprotected. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
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Average temperature in May
St. Louis, MO
- Average high temperature in May: 76.3°F
The warmest month (with the highest average high temperature) is July (89.1°F).
The month with the lowest average high temperature is January (39.9°F).
- Average low temperature in May: 57.2°F
The month with the highest average low temperature is July (71°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).
Average humidity in May
St. Louis, MO
- Average humidity in May: 66.5%
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 May
St. Louis, MO
- Average rainfall in May: 4.7"
The wettest month (with the highest rainfall) is May (4.7").
The driest month (with the least rainfall) is February (2.2").
Average rainfall days in May
St. Louis, MO
- Average rainfall days in May: 11.9 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 May
St. Louis, MO
- Average snowfall in May: 0"
The month with the highest snowfall is January (5.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
St. Louis, MO
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (4.7 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
St. Louis, MO
- Average daylight in May: 14h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in May: 8h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average UV index in May
St. Louis, MO
- Average UV index in May: 8
The months with the highest UV index are June, July and August (UV index 9).
The months with the lowest UV index are January and December (UV index 2).
St. Louis, Missouri, USA
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