Saint Louis — Water Temperature in May

Water Temperature Range

18°C

minimum

20°C

average

25°C

maximum

Get instant access to real-time water temperatures for this and all other locations with our iOS and Android apps.

Water Temperature Chart for Month

The chart shows the average daily water temperature for each day of the month based on historical data.

Table of Water Temperatures by Day of the Month for Previous Years

Day	2026	2025	2024	2023
MAY 1	-10°C	18°C	19°C	20°C
MAY 2	18°C	19°C	19°C	20°C
MAY 3	19°C	19°C	19°C	20°C
MAY 4	19°C	19°C	19°C	20°C
MAY 5	18°C	19°C	20°C	20°C
MAY 6	18°C	19°C	19°C	20°C
MAY 7	19°C	20°C	20°C	20°C
MAY 8	19°C	19°C	18°C	20°C
MAY 9	19°C	20°C	19°C	20°C
MAY 10	19°C	19°C	18°C	20°C
MAY 11	19°C	19°C	18°C	20°C
MAY 12	19°C	19°C	18°C	20°C
MAY 13	18°C	20°C	18°C	21°C
MAY 14	19°C	19°C	18°C	20°C
MAY 15	19°C	19°C	18°C	20°C
MAY 16	19°C	19°C	18°C	20°C
MAY 17	19°C	20°C	19°C	20°C
MAY 18	19°C	20°C	18°C	20°C
MAY 19	19°C	20°C	18°C	20°C
MAY 20	19°C	20°C	18°C	21°C
MAY 21	19°C	20°C	19°C	20°C
MAY 22	19°C	20°C	19°C	20°C
MAY 23	19°C	20°C	18°C	20°C
MAY 24	20°C	20°C	19°C	20°C
MAY 25	19°C	20°C	18°C	21°C
MAY 26	20°C	20°C	19°C	20°C
MAY 27	20°C	21°C	20°C	21°C
MAY 28	20°C	21°C	20°C	21°C
MAY 29	21°C	21°C	20°C	21°C
MAY 30	22°C	21°C	20°C	22°C
MAY 31	22°C	21°C	20°C	21°C

May: Climate and Swimming Opportunities

Average Night Air Temperature

22°C

Average Day Air Temperature

33°C

Precipitation Amount per Month

2 mm

Number of Rainy Days

Daylight per Day

13 hrs

Sunshine per Day

9 hrs

Average Wind Speed

13 km/h

Average Humidity

60%

At such water and air temperatures, swimming is pleasant and refreshing rather than hot. After you get in, it feels comfortable, and you’ll warm up quickly when you come out.