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.
5 days at a glance — tap a day to open it
Sunrise 06:20
Sunset 19:47
Sunset 19:47
First Quarter69% illuminated
Moonrise 16:06 · Moonset 00:11
Moonrise 16:06 · Moonset 00:11
Chart
Table
| Temperature | Rain chance | Cloud cover | Humidity | Pressure | Wind | UV Index | ||
|---|---|---|---|---|---|---|---|---|
| 00:00 |  Clear | 22 °C | 7% | 0% | 76% | 764 mm Hg | ENE 62° 2.81 (5.92) m/s | 0 |
| 01:00 | Clear | 21 °C | 8% | 0% | 77% | 764 mm Hg | ENE 77° 2.5 (5.53) m/s | 0 |
| 02:00 | Clear | 20 °C | 8% | 0% | 78% | 764 mm Hg | E 90° 2.31 (4.67) m/s | 0 |
| 03:00 | Clear | 19 °C | 8% | 9% | 76% | 764 mm Hg | ESE 103° 2.31 (5.22) m/s | 0 |
| 04:00 | Clear | 19 °C | 8% | 5% | 76% | 764 mm Hg | ESE 119° 1.69 (3.22) m/s | 0 |
| 05:00 | Clear | 19 °C | 8% | 6% | 76% | 764 mm Hg | ESE 103° 1.19 (1.72) m/s | 0 |
| 06:00 | Clear | 18 °C | 8% | 5% | 77% | 764 mm Hg | ESE 115° 1.39 (1.69) m/s | 0 |
| 07:00 |  Sunny | 19 °C | 7% | 0% | 75% | 764 mm Hg | E 88° 1.19 (1.42) m/s | 0.1 |
| 08:00 | Sunny | 19 °C | 5% | 0% | 66% | 764 mm Hg | E 86° 1.5 (1.92) m/s | 0.7 |
| 09:00 | Sunny | 22 °C | 3% | 4% | 56% | 764 mm Hg | ESE 106° 1.81 (2.19) m/s | 2 |
| 10:00 | Sunny | 25 °C | 1% | 0% | 46% | 764 mm Hg | ESE 108° 1.39 (5.39) m/s | 3.8 |
| 11:00 | Sunny | 27 °C | 1% | 0% | 37% | 764 mm Hg | SE 127° 0.81 (0.92) m/s | 5.7 |
| 12:00 | Sunny | 29 °C | 0% | 0% | 31% | 764 mm Hg | NNW 342° 0.39 (0.81) m/s | 7.2 |
| 13:00 | Sunny | 30 °C | 0% | 0% | 28% | 764 mm Hg | N 4° 1.39 (5.39) m/s | 8 |
| 14:00 | Sunny | 31 °C | 0% | 0% | 26% | 763 mm Hg | NNE 15° 1.69 (4.69) m/s | 7.4 |
| 15:00 | Sunny | 32 °C | 0% | 0% | 26% | 762 mm Hg | NNE 18° 2.11 (5.11) m/s | 5.9 |
| 16:00 | Sunny | 31 °C | 0% | 2% | 26% | 761 mm Hg | NNE 31° 2.39 (5.39) m/s | 3.9 |
| 17:00 | Sunny | 31 °C | 0% | 0% | 28% | 761 mm Hg | NE 55° 2.61 (7.61) m/s | 2 |
| 18:00 | Sunny | 30 °C | 1% | 0% | 34% | 761 mm Hg | ENE 78° 2.89 (3.11) m/s | 0.7 |
| 19:00 | Sunny | 28 °C | 1% | 0% | 42% | 761 mm Hg | ESE 113° 3.19 (4.5) m/s | 0.2 |
| 20:00 | Clear | 27 °C | 1% | 0% | 45% | 761 mm Hg | ESE 114° 3.19 (5.5) m/s | 0 |
| 21:00 | Clear | 26 °C | 1% | 0% | 48% | 761 mm Hg | ESE 119° 2.89 (5.61) m/s | 0 |
| 22:00 | Clear | 26 °C | 1% | 0% | 47% | 761 mm Hg | SE 141° 2.69 (5.61) m/s | 0 |
| 23:00 | Clear | 26 °C | 1% | 2% | 46% | 761 mm Hg | SSE 158° 2.11 (4.11) m/s | 0 |
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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.