5-day weather forecast St. Louis 18-08-2026

Weather forecast St. Louis today 18.08.2026: sunny, temperature from 19 °C to 34 °C.

Precipitation probability 24%. Wind up to 3.31 m/s (gusts 8.11 m/s). Air humidity 36–95%, atmospheric pressure 759–764 mm Hg, UV index up to 8.9.

Sunrise 06:17
Sunset 19:51
First Quarter37% illuminated
Moonrise 12:57 · Moonset 22:50
Chart
Table
Tue, Aug 18, 2026

Forecast from 19 °C to 34 °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)212020191919191921232429303133343432313028262625
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 (%)201010115389144010041100150000
Rain chance (%)8101211121214171424844321131021345

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)1.391.390.811.190.50.611.311.51.311.891.391.391.8121.811.511.111.52.113.313.112.813
Wind gust (m/s)2.221.920.811.220.610.726.312.142.112.531.751.812.332.612.612.642.331.61346.227.727.118.11
Wind direction (°)ENE 74°E 98°ENE 68°ENE 62°WSW 246°SW 226°SSE 165°SSW 210°SSW 208°SSW 202°SW 224°SW 232°SSW 211°SW 236°W 259°WSW 258°WSW 258°ENE 57°ESE 123°ESE 121°ESE 121°SE 124°SE 132°SE 131°

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 (%)788287868788919592857665655849454136374246606670

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)764764764764764763763763763763763763763762761761760760760759760760760760

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 Index00000000.20.82.14.16.48.28.98.36.64.42.30.80.20000

Air quality & pollen

Air quality
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
PM2.5 (µg/m³)14.316.818.319.320.320.921.519.914.512.812.512.813.91516.417.117.317.216.817.117.315.913.510.6
PM10 (µg/m³)14.41718.519.420.42121.62014.512.912.612.91415.216.517.317.417.316.917.217.416.113.610.7
Ozone (O₃) (µg/m³)18105200043168101125144160173182184175159141120988071
NO₂ (µg/m³)45.551.35454.553.551.347.541.832.621.512.67.54.62.81.81.93.26.310.614.81923.125.324.4
SO₂ (µg/m³)1.61.71.71.61.51.41.31.31.41.72.43.75.46.87.78.38.68.68.47.97.16.15.14
CO (µg/m³)297291294299304314325320287238200183176172169169174188207219218210202196
Tue, Aug 18, 2026

Frequently asked questions about the 5-day weather in St. Louis

What will the weather be like in St. Louis over the next 5 days?
Over the next 5 days in St. Louis the temperature is expected to range from about 18 to 34 °C. See the detailed hourly forecast for each of the 5 days in the charts above.
On which of the next 5 days will it rain in St. Louis?
The chance of rain in St. Louis over the next 5 days reaches 55%. Check the 5-day precipitation chart above to see exactly which days and hours bring rain.
How accurate is the 5-day weather forecast for St. Louis?
A 5-day forecast is fairly reliable: the first 2–3 days are usually very accurate, while days 4–5 may be refined. The data is updated several times a day, so check back before important plans.
Which of the next 5 days in St. Louis will be the warmest and which the coolest?
Over the next 5 days the temperature in St. Louis ranges from about 18 to 34 °C. Compare the warmest and coolest day on the temperature chart above.
Will it be windy in St. Louis over the next 5 days?
Over the next 5 days the wind in St. Louis picks up to 7 m/s. The windiest days are easy to spot on the wind chart above.
Which day of the week in St. Louis is best for a walk or a trip?
For a walk or a trip, pick the days with the lowest chance of rain (up to 55%) and light wind — easy to compare on the 5-day charts above.
How can I best use the 5-day forecast for St. Louis?
The first 2–3 days are reliable enough for firm decisions, while days 4–5 are a guide that sharpens as they approach. The forecast is updated several times a day, so check again before important plans.

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.