Last updated: June 24, 2025
In September, the average temperature in Houston, United States hovers around 18°C (65°F), providing a mild climate. However, be prepared for a temperature range that can dip to a chilly 2°C (36°F) or soar up to a warm 33°C (92°F). Expect about 119 mm (4.7 in) of precipitation spread over 9 days, contributing to an average humidity level of 74%. Whether you're packing an umbrella or sunscreen, be ready for a variety of weather experiences!
In September, in Houston, the average temperature is 18°C (65°F). The maximum can reach 33°C (92°F), while the minimum can be as low as 2°C (36°F). This temperature range makes Houston an ideal destination for travelers seeking both warm days and cool nights.
In Houston in September, the precipitation amount is 119 mm (4.7 in) occurring over a span of 9 days.
In Houston in September humidity is 74%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace that can make even short walks feel laborious, leading travelers to seek shade and refreshment more often.
In Houston 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 Houston.
UV Risk Categories
Weather in Houston varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Houston, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -7°C (20°F) | 37 mm (1.4 inches) | 84% | moderate |
| February Weather | -6°C (21°F) | 50 mm (2.0 inches) | 85% | moderate |
| March Weather | 2°C (36°F) | 60 mm (2.4 inches) | 84% | moderate |
| April Weather | 7°C (45°F) | 86 mm (3.4 inches) | 83% | very high |
| May Weather | 15°C (60°F) | 150 mm (5.9 inches) | 75% | very high |
| June Weather | 22°C (71°F) | 146 mm (5.7 inches) | 79% | very high |
| July Weather | 23°C (74°F) | 105 mm (4.1 inches) | 75% | very high |
| August Weather | 21°C (71°F) | 116 mm (4.6 inches) | 69% | very high |
| September Weather | 18°C (65°F) | 119 mm (4.7 inches) | 74% | very high |
| October Weather | 10°C (50°F) | 125 mm (4.9 inches) | 79% | moderate |
| November Weather | 2°C (35°F) | 54 mm (2.1 inches) | 88% | moderate |
| December Weather | -3°C (27°F) | 42 mm (1.6 inches) | 82% | low |