Last updated: June 24, 2025
In Saint Louis, United States, the average temperature in August hovers around 22°C (71°F), with a comfortable range that can dip to a minimum of 6°C (43°F) and peak at a balmy 34°C (94°F). Expect about 81 mm (3.2 in) of precipitation spread over 11 days, contributing to an average humidity level of 80%. This combination of warmth and moisture creates a vibrant atmosphere perfect for enjoying the season!
In August in Saint Louis, the average temperature is 22°C (71°F). Maximums can reach 34°C (94°F), and minimums can be as low as 6°C (43°F). Be prepared for a range of temperatures if you plan to travel during this time, as it can be pleasantly warm during the day but cooler at night.
In Saint Louis in August, the precipitation amount is 81 mm (3.2 in) over a span of 11 days.
In Saint Louis in August, humidity is 80%. With an average temperature of 22°C (71°F), this humidity feels like a warm, enveloping blanket, making travel slightly uncomfortable as skin becomes clammy and sweat clings to clothes.
In Saint Louis in August, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Saint Louis.
UV Risk Categories
Weather in Saint Louis varies notably across the year, with each month offering distinct climate conditions. This page compares August’s weather to other months in Saint Louis, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (24°F) | 55 mm (2.2 inches) | 88% | low |
| February Weather | -4°C (25°F) | 59 mm (2.3 inches) | 87% | moderate |
| March Weather | 2°C (35°F) | 58 mm (2.3 inches) | 85% | moderate |
| April Weather | 7°C (46°F) | 86 mm (3.4 inches) | 86% | very high |
| May Weather | 15°C (59°F) | 115 mm (4.5 inches) | 80% | very high |
| June Weather | 20°C (69°F) | 113 mm (4.5 inches) | 80% | very high |
| July Weather | 23°C (74°F) | 67 mm (2.7 inches) | 80% | very high |
| August Weather | 22°C (71°F) | 81 mm (3.2 inches) | 80% | very high |
| September Weather | 18°C (64°F) | 98 mm (3.9 inches) | 80% | high |
| October Weather | 11°C (52°F) | 120 mm (4.7 inches) | 84% | moderate |
| November Weather | 3°C (38°F) | 57 mm (2.2 inches) | 89% | moderate |
| December Weather | -1°C (31°F) | 63 mm (2.5 inches) | 86% | low |