Climate of Houston
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The Climate of Houston, Texas, United States is classified as humid subtropical. Houston's warmest month (on average) is July at about 94°F (33°C), and the coldest month being January at 61°F (16°C). The average yearly precipitation level is approximately 48 inches (1,220 mm). Houston has occasional severe weather, mostly in the form of flooding. Spring supercell thunderstorms sometimes bring tornadoes to the area. Houston has experienced tropical storms and hurricanes in the past that brought severe damage to the city.
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[edit] Seasonal observation
[edit] Summer
The summer months in Houston tend to be very humid and warm, with occasional summer thunderstorms every other day. During the summer months, the daily high temperature peaks at 94 °F (34 °C) at the end of July[1] with an average of 99 days per year above 90 °F (32 °C).[2] The air tends to feel still and the humidity (averaging over 90 percent relative humidity in the morning in the summer and around 60 percent in the afternoon[3]) results in a heat index higher than the actual temperature. Afternoon rains are common, and for most summer days Houston meteorologists predict at least some chance of rain. The hottest temperature ever recorded in Houston was 109 °F (43 °C) on September 4, 2000.[4]
Heat strokes in unprotected persons can occur in the city during the summer months. [5] Visitors to Houston tend to spend summer away from the city, venturing north in search of cooler temperatures.
Houston's heat and humidity has made air-conditioning an essential element in Houston's early survival. [6] To cope with the heat, residents use air conditioning in their automobiles and in many city structures. Before the widespread availability of air-conditioning in the 1930s, Houston did very poorly in the business scene, barely leveling the population at 100,000. In 1933, when air-conditioning finally became widespread, Houston's population jumped to 300,000. Air conditioning is considered the stimulus for the growth of Houston in 1950 when it became the most air-conditioned city in the world. [7] The 1950 census made Houston the 14th largest city in America with a population of 596,163. While air-conditioning is very popular in Houston, some residents have acclimated to the humidity and warm temperatures and feel that air-conditioning is only needed for the summer months alone.
[edit] Autumn
Autumn in Houston is fairly mild, with temperatures ranging from 79 °F during the day to 52 °F at night. [8] Fall is seen by residents as a mix of summer and winter, because of the warm days in September and much cooler days in October.
Early October brings at least two large cold fronts to start the cooling trend into winter. The cold fronts can bring heavy, flooding rains and are more frequent throughout October and November.[9][10]
[edit] Winter
Winter is the coolest season in Houston. Winters in Houston are chilly and temperate. While the average high in January, the coldest month, is 61 °F (16 °C), Houston sees an average of 18 days per year of 32 °F (0 °C) or less.[11] The coldest temperature ever recorded in Houston was 5 °F (−15 °C) on January 23, 1940.
In November, temperatures get colder with wet cold fronts. Throughout December, cold fronts, often called "blue northers" by residents, [12] batter the city with cold rain, strong wind chill, ice, and sometimes sleet. Early January starts with cold temperatures, yet warm up through February.
[edit] Snow and ice
Snow is very rare in Houston, with an event occurring every 4 years or so. Snow has fallen approximately 30 times since 1895,[13] the most recent was on December 24, 2004, the first Christmas Eve snowfall. Snow was also expected for Christmas Day,[14]but did not accumulate.
During El Niño in winter, temperatures can drop rapidly in the American South. If a Blue Norther hits the city with freezing temps, and there is a sufficient amount of moisture in Texas, large sleet and ice storms can occur in the city. These storms can cause heavy damage to traffic, and can close schools and businesses. This event has occurred in the past, most recently in 1991 and 2007.
[edit] Spring
Spring comes with a very mild warm up from winter, lasting from March 20 through May. Temperatures stay fairly low, not usually warming up above 77°F. Often during spring, supercell thunderstorms can occur, [15] prompting Houston's 10-month long "growing season" to begin. Spring also sees the return of many animals, including butterflies and mosquitoes, to return to Houston's infamous warm climate.
Spring slowly diminishes the colder winter temperatures, yet freezing weather can still occur on some nights in late March.
[edit] Precipitation
Rainfall is the most common form of precipitation in Houston. The wettest month is May, with 5.6 inches of rain. The city receives 47.9 inches of rain in an average year. The most precipitation to fall in one year was 72.86 inches which occurred in 1900. Houston has received less than 20 inches of rain only once: 17.66 inches in 1917.[16] Flash flood warnings are common all year, and due to the flat landscape, heavy rains can be a threat to the city.
Sleet, snow and ice are unusual, and sometimes never occur at all during the winter. Hail can accumulate, yet only in small quantities. Frozen precipitation does not survive the warmer temperatures.
[edit] Extreme weather
Houston has occasional severe weather, mostly in the form of flooding. The effects of Hurricane landfall can bring severe damage to the city and region.
[edit] Tropical storms
Because of Houston's close proximity to the Caribbean Sea and Gulf of Mexico, the city has a significant chance of receiving hurricanes and tropical storms every hurricane season.
Houston's history of hurricanes stretches back to 1837, when the Racer's Storm passed just to the south of the town, raising water levels four feet.[17] The Great Hurricane of 1900, which razed nearby Galveston, also passed over Houston, but the hurricane weakened to a tropical storm by the time it reached Houston. [18] Hurricane Carla directly hit the city in 1961, causing major damage to the city. At the time of landfall, Carla was the most powerful tropical system to affect the Texas coast in over 40 years, [19] and many would follow its destructive path. In 1983, the city experienced a direct hit in the form of Hurricane Alicia, causing one billion dollars damage to the city and striking during a down period in the city's economy.
The most destructive and costly natural disaster in city history was Tropical Storm Allison of 2001, [20] which dumped 37 inches of rain, and completely overwhelmed the area's flood control system. It is the only tropical storm in history to make the retired names list.
Hurricane Rita, a category 5 storm, threatened the city in 2005, prompting mass evacuation. However, the storm veered off to the east before landfall and caused minimal damage.
[edit] Flooding
Flooding is a major threat all year in Houston, particularly in fall and winter. The marshland around Houston easily floods, due to the lack of land height. In fall, large cold fronts batter the city, and flooding regularly happens. Many of the bayous in the city are close to flat land, so in the event of an overflow, many homes and businesses could be damaged. Many of the city's older suburbs have outdated sewer systems, which can't drain water in the event of flash flooding. Due to these faults, flooding is the city's most common threat.
[edit] Tornadoes
Unlike much of Texas, Houston is not considered a part of Tornado Alley, but smaller tornadoes are common during severe weather. They are most likely to be found along frontal boundaries of an air mass during the spring months. The most common tornadoes in Houston measure F1 on the old Fujita scale, which can destroy or damage one or two buildings. The strongest recorded tornado in Houston history was an F4 on November 21, 1992, part of a large outbreak of tornadoes. [21]
[edit] Environmental issues
Houston is well known for its oil and petrochemical industries, which are leading contributors to the city's economy. The industries located along the ship channel, [22] coupled with a growing population, has caused a considerable increase in air pollution for the city each year. Houston has excessive ozone levels and is ranked among the most ozone-polluted cities in the United States.[23] Ground-level ozone, or smog, is Houston’s predominate air pollution problem. In 2000, Houston earned the title of "most polluted city in America" by its standards and was ordered by the federal government to clean up pollution by 2007. [24][25] Houston has introduced many programs since the announcement to reduce air pollution in the city.
The most notable project was the METRORail light rail system constructed in 2004. The light rail system was designed to encourage Houstonians to utilize public transportation instead of their automobiles.
Houston has also seen recent improvements to the city's waterways. The banks of Buffalo Bayou have been cleaned of garbage and have been turned into jogging trails and parks. Since the mid-1990s, Houston has seen a great increase in wildlife along the bayou due to many successful cleaning attempts.[26]
The Port of Houston has not seen any major cleaning attempts and continues to be polluted from the local refineries and industries.
Global warming is a potential factor in the city's weather. Houston often sees ozone damage from both pollution and global warming.[27] Six of Houston's hottest recorded temperatures have been since 1986.[28] The warmest, in 2000, was 109 degrees F. Many winters in Houston have seen near-record high temperatures, going as high as 85 degrees in early December.
[edit] Weather chart
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average high °F (°C) | 61 (16) | 66 (18) | 73 (22) | 79 (26) | 85 (29) | 91 (32) | 94 (34) | 93 (33) | 89 (31) | 82 (27) | 72 (22) | 65 (18) | 79 (26) |
| Rec high °F (°C) (year) | 84 (29) (1975) | 91 (33) (1986) | 96 (36) (1946) | 95 (35) (1987) | 99 (37) (1996) | 103 (39) (1980) | 105 (41) (1939) | 107 (42) (1980) | 109 (43) (2000) | 97 (36) (1938) | 90 (32) (1934) | 85 (29) (1995) | 109 (43) (2000) |
| Average low °F (°C) | 41 (5) | 44 (6) | 51 (10) | 58 (14) | 65 (18) | 71 (21) | 73 (22) | 73 (22) | 68 (20) | 59 (15) | 50 (10) | 44 (6) | 58 (14) |
| Rec low °F (°C) (year) | 5 (-15) (1940) | 14 (-10) (1951) | 22 (-6) (2002) | 31 (-1) (1987) | 44 (7) (1978) | 50 (10) (1970) | 62 (17) (1990) | 60 (16) (1992) | 46 (8) (1942) | 29 (-2) (1993) | 19 (-7) (1976) | 7 (-14) (1989) | 5 (-15) (1940) |
| Average precipitation: inches (mm) |
3.9 (99) | 2.9 (74) | 3.5 (89) | 3.6 (91) | 5.6 (142) | 5.1 (129) | 3.4 (86) | 3.7 (94) | 4.3 (109) | 4.7 (119) | 3.7 (94) | 3.6 (91) | 47.9 (1217) |
| Maximum precipitation: inches (mm) (year) |
13.11 (333) (1891) | 9.80 (249) (1959) |
10.66 (271) (1922) | 10.92 (277) (1976) | 15.87 (403) (1907) | 19.21 (488) (2001) | 14.80 (376) (1900) | 15.43 (392) (1915) | 13.37 (340) (1913) | 17.64 (448) (1949) | 14.10 (358) (1943) | 14.38 (365) (1923) | 72.86 (1851) (1900) |
| Source: Weatherbase[29] | |||||||||||||
[edit] Notes
- ^ Monthly Averages for Houston, Texas. The Weather Channel, Retrieved on March 10, 2007
- ^ National Climatic Data Center. U.S. Department of Commerce, Retrieved on March 10, 2007
- ^ National Relative Humidity. Department of Meteorology at the University of Utah, Retrieved on March 10, 2007
- ^ History for Houston Intercontinental, Texas on Monday, September 4, 2000. Weather Underground, Retrieved on March 10, 2007
- ^ Temperature Rising? Could be Heat Stroke. Texas Medical Center News, Retrieved on March 11, 2007
- ^ How Air Conditioning Changed America. The Old House Web, Retrieved on March 11, 2007
- ^ A Short History. Houston Geological Auxiliary, Retrieved on March 11, 2007
- ^ Information/Data — All About Houston. Greater Houston Partnership, Retrieved on January 9, 2006.
- ^ October 2nd, 2006 flash flood, created by a large cold front
- ^ Significant Houston Area Floods. Weather Research Center, Retrieved on January 9, 2006.
- ^ National Climatic Data Center. U.S. Department of Commerce, Retrieved on March 10, 2007
- ^ Blue Norther. TSHA Handbook of Texas, Retrieved on March 11, 2007
- ^ Houston Snow. Weather Research Center, Retrieved on January 9, 2006.
- ^ WeatherBug, December 24, 2004 at 6:30 PM CST
- ^ Severe Thunderstorms. National Weather Service Forecast Office Houston/Galveston, Texas, Retrieved on March 11, 2007
- ^ Houston's Annual Topn 10 List. National Weather Service, Houston/Galveston, Texas. January 30, 2006. Last accessed January 3, 2006.
- ^ http://www.srh.noaa.gov/lch/research/txearly19hur.php Early Texas Hurricane History, 1800-1850, Retrieved on March 10, 2007
- ^ Remembering the Great Hurricane, September 8, 1900. Galveston County Daily News, Retrieved on March 11, 2007
- ^ Hurricane Carla, September 9-12, 1961. National Weather Service, Retrieved on March 11, 2007
- ^ [http://www.srh.noaa.gov/hgx/projects/allison01.htm Tropical Storm Allison Floods June 5-9, 2001]. National Weather Service Forecast Office Houston/Galveston, Texas, Retrieved on March 11, 2007
- ^ Cluster Tornado Outbreak in Houston, TX. Stormtrack Library, Retrieved on March 10, 2007.
- ^ "Summary of the Issues", Citizens League for Environmental Action Now , 2004-08-01. Retrieved on 2006-02-17.
- ^ "State of the Air 2005, National and Regional Analysis ", American Lung Association, 2005-03-25. Retrieved on 2006-02-17.
- ^ "Catching Our Breath", The University of Texas at Austin. Retrieved on 2006-02-17.
- ^ Lonely Planet Guide to Texas, page 304
- ^ Texas Monthly Guide to Houston Edition 1996 ISBN 0-87719-272-3 Pages 9 through 10
- ^ Houston Chronicle, page B12 (Ozone warnings)
- ^ Historical Weather for Houston, Weatherbase, retrieved March 11, 2007
- ^ Historical Weather for Houston. Weatherbase, Retrieved on March 10, 2007
