Houston Weather in September
September's weather still feels hot at Houston, Texas. While the temperature has dropped from the previous months, afternoon humidity has climbed.
This page gives detailed information on the typical September temperature, precipitation, sun, humidity, wind and storms for Houston. The numbers here are historical averages based on temperature and rainfall measurements gathered at Houston Hobby Airport and other climate data from George Bush Intercontinental Airport.
|89 °F||September average high||32 °C|
|73 °F||September average low||23 °C|
|16 days||90 °F max. or more (32 °C)|
|7 days||70 °F min. or less (21 °C)|
Nearly every September day warms to over 80 degrees Fahrenheit (27 degrees Celsius) in Houston. The city can reach 100 °F (38 °C) now, although days that hot don't happen this late every summer.
The thermometer dips to 60 °F (16 °C) or below on an average of 1 night during the month.
|5.8 in||total precipitation||146 mm|
|10 days||of rain|
Half the time, Houston receives 3.2 to 8.5 inches (81 to 215 mm) of rainfall in September. One in four years has drier weather, while another one in four is wetter.
|9 days||clear skies|
The sun's rays reach the ground in Houston during 66 percent of daylight hours on average in September, for a total of 244 hours in the month. Typically on 9 days this month the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in September at Houston lasts for 12 hours and 19 minutes a day on average. The longest day of the month is the 1st with 12 hours and 45 minutes of daylight. By the end of the month, the days have shortened to 11:53 from sunrise to sunset. These durations can vary by a minute or two from year to year.
|77 %||September average humidity|
September is the most humid time of year for Houston. The relative humidity usually peaks at 93 percent in the morning then drops to 57 percent by mid afternoon.
|Local Time||12 am||3 am||6 am||9 am||12 pm||3 pm||6 pm||9 pm|
|6.5 mph||September wind speed average||10.5 kph|
September is less windy than most other months in Houston.
|3 days||rainfall of 0.5 inches (13 mm) or more|
|8 days||with thunderstorms in September|
|16 %||chance a named storm approaches|
There's a 6 percent probability that a hurricane will approach within 100 miles (165 km) of Houston during September. The chance of a major category 3 to 5 hurricane reaching the area is 1 percent.
The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals. The named storm probabilities come from the Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division.