The "500-year" flood from Tropical Storm Allison

The Climate of Houston 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. Summary Tropical Storm Allison just before landfall in Texas on June 5, 2001. ... Summary Tropical Storm Allison just before landfall in Texas on June 5, 2001. ... 2 B C D E F G 9 H I J K L M N O Categories: | | | | | | | ... S ... Nickname: Location in the state of Texas Coordinates: Country United States State Texas Counties Harris County Fort Bend County Montgomery County Incorporated June 5, 1837 Government  - Mayor Bill White Area  - City  601. ... Satellite view of a supercell A supercell is a severe thunderstorm with a deep rotating updraft (a mesocyclone) [1]. Supercell thunderstorms are the largest, most severe class of single-cell thunderstorms. ... A tornado in central Oklahoma. ...

Seasonal observation

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] Humidity is the quantity of moisture in the air. ... WARM is an American adult contemporary radio station based in Harrisburg, Pennsylvania broadcasting at 103. ... Summer is a season of the year that is defined as beginning on June 21st, and ending in September in the Northern Hemisphere. ... This does not adequately cite its references or sources. ... The heat index (HI) or humidex is an index that combines air temperature and relative humidity to determine an apparent temperature — how hot it actually feels. ... Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. ... Fig. ...

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. In the broadest sense air conditioning can refer to any form of cooling, heating, ventilation or disinfection that modifies the condition of air, typically for thermal comfort. ... 1933 (MCMXXXIII) was a common year starting on Sunday. ...

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. Autumn (also known as fall in North American English) is one of the four temperate seasons, the transition from summer into winter. ...

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] In meteorology, a weather front is a boundary between two air masses with differing characteristics (e. ...

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. Winter is one of the four seasons of temperate zones. ...

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. In meteorology, a weather front is a boundary between two air masses with differing characteristics (e. ...

Snow and ice

December 24th Snowstorm, shown on satellite.

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. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The 2004 Christmas Eve Snowstorm was an extremely rare weather event that took place in Louisiana and Texas in the United States on December 24, 2004. ...

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. Chart of ocean surface temperature anomaly [°C] during the last strong El Niño in December 1997 El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. ... 1991 (MCMXCI) was a common year starting on Tuesday of the Gregorian calendar. ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ...

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 is one of the four seasons of temperate zones, the transition from winter into summer. ... March 20 is the 79th day of the year in the Gregorian Calendar (80th in leap years). ... May is the fifth month of the year in the Gregorian Calendar and one of seven Gregorian months with the length of 31 days. ... This article is about the insect; for the WWII aircraft see De Havilland Mosquito. ...

Spring slowly diminishes the colder winter temperatures, yet freezing weather can still occur on some nights in late March.

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. In meteorology, precipitation is any kind of water that falls from the sky as part of the weather. ... Lower Antelope Canyon was carved out of sandstone by flash floods A Flash Flood is a rapid flooding of geomorphic low-lying areas (washes), rivers and streams, caused by the intense rainfall associated with a thunderstorm, or multiple training thunderstorms. ...

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.

Extreme weather

Houston has occasional severe weather, mostly in the form of flooding. The effects of tropical cyclone landfall can bring severe damage to the city and region. A flood (in Old English flod, a word common to Teutonic languages; compare German Flut, Dutch vloed from the same root as is seen in flow, float) is an overflow of water, an expanse of water submerging land, a deluge. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ... Hurricane Charley making landfall on August 13, 2004 at its peak intensity. ...

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. Map of Central America and the Caribbean Caribbean Sea from space (top left). ... This article is about weather phenomena. ... Hurricane seaons can refer to : The Atlantic hurricane season The Pacific hurricane season This is a disambiguation page — a navigational aid which lists pages that might otherwise share the same title. ...

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. Queen Victoria, Queen of the United Kingdom (1837 - 1901) 1837 (MDCCCXXXVII) was a common year starting on Sunday (see link for calendar). ... The 1837 Racers Storm was one of the most powerful and destructive hurricanes in the 19th century, causing heavy damage to many cities on its 2,000+ mile path. ... Lowest pressure 936 mbar (hPa; 27. ... Hurricane Carla, a Category 5 at peak intensity, was one of the most powerful storms to ever strike the United States. ... 1961 (MCMLXI) was a common year starting on Sunday (the link is to a full 1961 calendar). ... 1983 (MCMLXXXIII) was a common year starting on Saturday of the Gregorian calendar. ... Hurricane Alicia was the only major hurricane of the 1983 Atlantic hurricane season. ...

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. 2 B C D E F G 9 H I J K L M N O Categories: | | | | | | | ... 2001 (MMI) was a common year starting on Monday of the Gregorian calendar. ...

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. Lowest pressure 895 mbar (hPa)[1] Damages $10 billion (2005 USD)[1] Fatalities 7 direct, 113 indirect Areas affected Bahamas, Florida, Cuba, Yucatán Peninsula, Louisiana, Texas, Mississippi, Arkansas Part of the 2005 Atlantic hurricane season Hurricane Rita is the fourth-most intense Atlantic hurricane ever recorded and the most... The Saffir-Simpson Hurricane Scale is a scale classifying most Western Hemisphere tropical cyclones that exceed the levels of tropical depression and tropical storm and thereby become hurricanes; the categories it divides hurricanes into are distinguished by the intensities of their respective sustained winds. ... 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ...

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. Lower Antelope Canyon was carved out of sandstone by flash floods A Flash Flood is a rapid flooding of geomorphic low-lying areas (washes), rivers and streams, caused by the intense rainfall associated with a thunderstorm, or multiple training thunderstorms. ...

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] An outline of Significant Tornado Alley in the United States, where the highest percentage of violent tornadoes occur Tornado Alley is a colloquial term most often used in reference to the area of the United States in which tornadoes are most frequent. ... For other uses of Tornado, see Tornado (disambiguation). ... In meteorology, an air mass is a large volume of air having fairly uniform characteristics of temperature, atmospheric pressure, and water vapor content. ... The Fujita scale (F-Scale), or Fujita-Pearson scale, rates a tornados intensity by the damage it inflicts on human-built structures and sometimes on vegetation. ... November 21 is the 325th day of the year (326th in leap years) in the Gregorian calendar. ... 1992 (MCMXCII) was a leap year starting on Wednesday. ... The November 1992 Tornado Outbreak was a three-day tornado outbreak that struck large parts of the eastern and Midwestern U.S. on November 21-23. ...

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. It has been suggested that Pollutant be merged into this article or section. ... For other uses, see Ozone (disambiguation). ... Victorian London was notorious for its thick smogs, or pea-soupers, a fact that is often recreated to add an air of mystery to a period costume drama. ...

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. METRORail is the light rail service in Houston, Texas, United States that started on January 1, 2004. ... This article is about light rail systems in general. ...

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] Map of the Buffalo Bayou and associated watershed Buffalo Bayou at this location, just south of San Felipe Dr. Buffalo Bayou is a main waterway flowing through Houston, Texas, USA. It begins on the west side of the city and flows east to the Houston Ship Channel. ...

The Port of Houston has not seen any major cleaning attempts and continues to be polluted from the local refineries and industries. The Port of Houston is the port of Houston, Texas, the fourth largest city in the United States. ... Water pollution is a large set of adverse effects upon water bodies such as lakes, rivers, oceans, and groundwater caused by human activities. ...

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. Global mean surface temperatures 1850 to 2006 Mean surface temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980 Global warming is the observed increase in the average temperature of the Earths atmosphere and oceans in recent decades and the projected... For other uses, see Ozone (disambiguation). ... 1986 (MCMLXXXVI) was a common year starting on Wednesday of the Gregorian calendar. ...

Weather chart

Fahrenheit is a temperature scale named after the German physicist Daniel Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ...

Notes

March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... January 9 is the 9th day of the year in the Gregorian calendar. ... For the Manfred Mann album, see 2006 (album). ... January 9 is the 9th day of the year in the Gregorian calendar. ... For the Manfred Mann album, see 2006 (album). ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... January 9 is the 9th day of the year in the Gregorian calendar. ... For the Manfred Mann album, see 2006 (album). ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... shelby was here 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... August 1 is the 213th day of the year in the Gregorian calendar (214th in leap years), with 152 days remaining. ... For the Manfred Mann album, see 2006 (album). ... February 17 is the 48th day of the year in the Gregorian calendar. ... 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ... March 25 is the 84th day of the year in the Gregorian calendar (85th in leap years). ... For the Manfred Mann album, see 2006 (album). ... February 17 is the 48th day of the year in the Gregorian calendar. ... For the Manfred Mann album, see 2006 (album). ... February 17 is the 48th day of the year in the Gregorian calendar. ... Lonely Planet logo Lonely Planet Publications (usually known as Lonely Planet or LP for short) claims to be the largest independently owned travel guidebook publisher in the world. ... The Houston Chronicle is a daily newspaper in Houston, Texas, United States. ... March 11 is the 70th day of the year in the Gregorian calendar (71st in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... March 10 is the 69th day of the year in the Gregorian calendar (70th in leap years). ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ...

External links

• Weather Averages for Houston
• Comparison with month average and actual temps