Last updated: June 24, 2025
In Manassas, United States, the average temperature for September hovers around 22°C (72°F), making it a warm and inviting destination. However, be prepared for temperature fluctuations—with a minimum dipping to 5°C (42°F) and the maximum soaring to 37°C (99°F). During this month, expect 95 mm (3.7 in) of precipitation spread over 11 days, contributing to an average humidity level of 68%. Enjoy the diverse climate while planning your activities!
In September in Manassas, the average temperature is 22°C (72°F). Maximums can reach 37°C (99°F) and minimums can drop as low as 5°C (42°F). This means that travelers should be prepared for a wide range of temperatures, ensuring they pack both lighter clothing for the warm days and warmer layers for the cooler evenings.
In Manassas in September, the total precipitation amount is 95 mm (3.7 in) spread over 11 days.
In Manassas in September humidity is 68%. With an average temperature of 22°C (72°F), this humidity feels like a warm embrace, slightly stifling but still manageable for traveling, creating an atmosphere that encourages leisurely outdoor activities while prompting occasional breaks for refreshment.
In Manassas 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 Manassas.
UV Risk Categories
Weather in Manassas varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Manassas, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 3°C (37°F) | 60 mm (2.4 inches) | 86% | moderate |
| February Weather | 5°C (41°F) | 95 mm (3.7 inches) | 86% | moderate |
| March Weather | 8°C (47°F) | 79 mm (3.1 inches) | 86% | high |
| April Weather | 14°C (57°F) | 102 mm (4.0 inches) | 84% | very high |
| May Weather | 19°C (67°F) | 125 mm (4.9 inches) | 78% | very high |
| June Weather | 24°C (75°F) | 108 mm (4.3 inches) | 79% | very high |
| July Weather | 27°C (81°F) | 109 mm (4.3 inches) | 70% | very high |
| August Weather | 25°C (78°F) | 146 mm (5.7 inches) | 59% | very high |
| September Weather | 22°C (72°F) | 95 mm (3.7 inches) | 68% | very high |
| October Weather | 17°C (62°F) | 108 mm (4.3 inches) | 80% | high |
| November Weather | 8°C (47°F) | 85 mm (3.3 inches) | 86% | moderate |
| December Weather | 5°C (41°F) | 90 mm (3.6 inches) | 85% | moderate |