5-day weather forecast St. Louis 21-08-2026

Weather forecast St. Louis Friday, August 21 21.08.2026: sunny, temperature from 18 °C to 32 °C.

Precipitation probability 8%. Wind up to 3.19 m/s (gusts 7.61 m/s). Air humidity 26–78%, atmospheric pressure 761–764 mm Hg, UV index up to 8.

Sunrise 06:20
Sunset 19:47
First Quarter69% illuminated
Moonrise 16:06 · Moonset 00:11
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Table

Forecast from 18 °C to 32 °C and precipitation

Temperature & Precipitation
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Temperature (°C)222120191919181919222527293031323131302827262626
Precipitation (mm/hr)000000000000000000000000

Cloud cover and precipitation probability

Cloud cover & Rain chance
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Cloud cover (%)000956500400000020000002
Rain chance (%)788888875311000000111111

Wind speed and direction

Wind & Wind gust
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Wind (m/s)2.812.52.312.311.691.191.391.191.51.811.390.810.391.391.692.112.392.612.893.193.192.892.692.11
Wind gust (m/s)5.925.534.675.223.221.721.691.421.922.195.390.920.815.394.695.115.397.613.114.55.55.615.614.11
Wind direction (°)ENE 62°ENE 77°E 90°ESE 103°ESE 119°ESE 103°ESE 115°E 88°E 86°ESE 106°ESE 108°SE 127°NNW 342°N 4°NNE 15°NNE 18°NNE 31°NE 55°ENE 78°ESE 113°ESE 114°ESE 119°SE 141°SSE 158°

Air humidity

Humidity
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Humidity (%)767778767676777566564637312826262628344245484746

Atmospheric pressure

Pressure
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
Pressure (mm Hg)764764764764764764764764764764764764764764763762761761761761761761761761

Ultraviolet index

UV Index
Time00:0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00
UV Index00000000.10.723.85.77.287.45.93.920.70.20000

St. Louis on the map

Data Sources & Methodology

Our weather forecasts are powered by a professional weather data provider that aggregates data from national weather services, satellite observations, radar networks, and over 80,000 weather stations worldwide. Forecast data is updated multiple times daily. We convert raw data into clear summaries — wind speed in m/s, pressure in mmHg — so you can plan your day with confidence.