Last updated: June 24, 2025
In Vienna, United States, the average temperature in September is a pleasant 21°C (70°F). However, temperatures can vary widely, with a minimum of 5°C (42°F) and a maximum of 37°C (98°F). Visitors should be prepared for some rain, as the area experiences approximately 106 mm (4.2 in) of precipitation over 9 days. Additionally, the average humidity hovers around 73%, making it a warm and somewhat muggy month to explore!
In September in Vienna, the average temperature is 21°C (70°F). Maximum temperatures can reach 37°C (98°F), while minimums can dip as low as 5°C (42°F). Travelers should be prepared for a wide range of temperatures, so it's advisable to pack both lightweight clothing and warmer layers for the cooler evenings.
In Vienna in September, the total precipitation amount is 106 mm (4.2 in), spread over the course of 9 days.
In Vienna in September, humidity is 73%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace that can make outdoor activities feel sweltering, so it's essential to stay hydrated and take breaks in the shade while exploring.
In Vienna in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Vienna.
UV Risk Categories
Weather in Vienna varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Vienna, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 1°C (34°F) | 94 mm (3.7 inches) | 88% | moderate |
| February Weather | 4°C (39°F) | 125 mm (4.9 inches) | 88% | moderate |
| March Weather | 7°C (46°F) | 115 mm (4.5 inches) | 88% | high |
| April Weather | 12°C (55°F) | 147 mm (5.8 inches) | 86% | very high |
| May Weather | 18°C (65°F) | 153 mm (6.0 inches) | 82% | very high |
| June Weather | 22°C (72°F) | 163 mm (6.4 inches) | 84% | very high |
| July Weather | 25°C (77°F) | 119 mm (4.7 inches) | 82% | very high |
| August Weather | 24°C (75°F) | 121 mm (4.8 inches) | 73% | very high |
| September Weather | 21°C (70°F) | 106 mm (4.2 inches) | 73% | very high |
| October Weather | 15°C (60°F) | 120 mm (4.7 inches) | 81% | high |
| November Weather | 7°C (45°F) | 82 mm (3.2 inches) | 89% | moderate |
| December Weather | 4°C (39°F) | 118 mm (4.6 inches) | 86% | moderate |