5-day weather forecast St. Louis Oct 18, 2026

9°9–20° · Clear

Weather forecast St. Louis today Oct 18, 2026: sunny, temperature from 9 °C to 20 °C.

Precipitation probability 1%. Wind up to 3.81 m/s (gusts 7.33 m/s). Air humidity 23–45%, atmospheric pressure 770–774 mm Hg, UV index up to 4.5.

Sunrise 07:13
Sunset 18:18
First Quarter58% illuminated
Moonrise 14:46 · Moonset does not set today
Chart
Table
Sun, Oct 18, 2026

Forecast from 9 °C to 20 °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)11111010109999111315161819202019181616151514
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 (%)000000000000000000000050
Rain chance (%)111111111111000000111111

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)2.52.392.612.692.612.612.612.692.693.113.53.813.813.693.53.313.393.1932.89332.692.39
Wind gust (m/s)4.534.694.834.724.724.534.724.835.035.335.725.615.315.034.614.424.534.615.116.2277.336.335.19
Wind direction (°)SE 137°SE 145°SSE 151°SSE 157°SSE 162°SSE 162°SSE 162°SSE 166°SSE 164°SSE 167°S 169°SSE 166°S 169°S 172°S 173°SSE 167°SSE 164°SSE 160°SSE 147°SE 143°SE 146°SSE 158°SSE 167°SSE 167°

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 (%)434445444341393837333129262423232326303234363840

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)773773773773773773773774774774774773773773771770770770770770771771771771

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 Index0000000000.61.634.14.54.131.60.6000000

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)19.615.412.310.298.58.48.89.58.56.66.46665.95.85.66.27.57.77.67.47.3
PM10 (µg/m³)19.915.712.510.49.28.78.699.78.97.67.87.57.47.37.276.87.18.48.68.48.17.9
Ozone (O₃) (µg/m³)152329353837333235414857687682858475625146444240
NO₂ (µg/m³)48.237.629.221.315.914.716.116.414.210.98.16.14.43.32.41.92.96.411.415.216.7171716.6
SO₂ (µg/m³)3.62.82.21.71.31.21.21.41.61.92.32.93.53.93.93.83.53.22.72.42.221.91.8
CO (µg/m³)252214187165152153162170173173170159143132128129136155181199202196191187
Sun, Oct 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 9 to 25 °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 12%. 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 9 to 25 °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 4 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 12%) 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.

Will I need an umbrella or sunscreen in St. Louis this week?

Rain reaches a 12% chance across the next 5 days, so pack something waterproof for the wettest of them — the daily strip above shows which. Today’s UV index peaks at 4.5; sunscreen is worth it from about 3 upwards.

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.