Weather in May
Temperature
May's arrival in St. Louis, Missouri, signals a subtle increase in average high-temperatures, moving from April's refreshing 67.5°F (19.7°C) to a moderately hot 76.3°F (24.6°C). St. Louis observes an average low-temperature of 57.2°F (14°C) during May nights.Humidity
In St. Louis, the average relative humidity in May 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
May through October are months without snowfall in St. Louis.Daylight
The average length of the day in May in St. Louis, Missouri, is 14h and 17min.On the first day of May in St. Louis, Missouri, 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 value of 8 to 10 symbolizes a very high health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high daily UV index of 8 during May translates into the following directions:
Ensure you're always protected. Unprotected skin can get damaged in moments. 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.
Frequently asked questions
What is the usual temperature for St. Louis in May?
What is the average humidity in May in St. Louis?
What is the wettest month in St. Louis?
How many days does it rain in May in St. Louis?
When it does not snow in St. Louis?
Does it snow in St. Louis in May?
How many hours of daylight does St. Louis have in May?
When are sunrise and sunset in May in St. Louis?
How long on average sun shines in May in St. Louis?
How high is the UV index in May in St. Louis?
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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