Houston, Texas Weather - Annual trend, Monthly average range of temperature and Precipitation data

Houston, Texas Weather - Annual trend, Monthly average range of temperature and Precipitation data

Houston's climate is classified as humid subtropical.

While not necessarily part of "Tornado Alley" like much of the rest of Texas, Spring supercell thunderstorms do sometimes bring tornadoes to the area.

Prevailing winds are from the south and southeast during most of the year, bringing heat across the continent from the deserts of Mexico and moisture from the Gulf of Mexico.

During the summer months, it is common for the temperature to reach over 90 °F (32 °C), with an average of 99 days per year above 90 °F (32 °C). However, the humidity results in a heat index higher than the actual temperature. Summer mornings average over 90 percent relative humidity and approximately 60 percent in the afternoon. Scattered afternoon showers and thunderstorms are common in the summer.

Winters in Houston are fairly temperate. The average high in January, the coldest month, is 62 °F (17 °C), while the average low is 39 °F (4 °C).

Snowfall is generally rare. Houston receives a high amount of rainfall annually, averaging about 54 inches a year. These rains tend to cause floods over portions of the city.

Houston has excessive ozone levels and is ranked among the most ozone-polluted cities in the United States. Ground-level ozone, or smog, is Houston’s predominant air pollution problem, with the American Lung Association rating the metropolitan area's ozone level as the 8th worst in the United States in 2011. The industries located along the ship channel are a major cause of the city's air pollution.