Climate
Tulsa is situated near the heart of Tornado Alley and has a temperate climate of the continental variety with a yearly average temperature of 61°F and an average rainfall of 39 in (99 cm). As is typical temperate zones, weather patterns vary by season with occasional extremes in temperature and rainfall.
Primarily in the spring and early summer months, the city is subjected to severe thunderstorms containing large hail, damaging winds, or small tornadoes, providing the area with a disproportionate share of its annual rainfall. Severe weather is not limited, though, to this season; on December 5, 1975, for example, Tulsa experienced a tornado. Due to its potential for major flooding events, the city has developed one of the most extensive flood control systems in the nation. A comprehensive flood management plan was developed in 1984 following a severe flood caused by a stalled weather front that dropped 15 inches of rain overnight, killing 14, injuring 288, and destroying 7,000 buildings totaling $180 million in damage. In the early 1990s and again in 2000, FEMA honored Tulsa as leading the nation in flood plain management.
Temperatures of 40 °C (100 °F) or higher are often observed from July to early September, usually accompanied by high humidity brought in by southerly winds. Lack of air circulation due to heat and humidity during the summer months leads to higher concentrations of ozone, prompting the city to release "Ozone Alerts," encouraging all parties to do their part in complying with the Clean Air Act and E.P.A. standards. The Autumn season is usually short, consisting of pleasant, sunny days followed by cool nights. Winter temperatures, while generally mild, occasionally experience extremes below -20 °C (0 °F) while annual snowfall averages about 9 inches.
(Source: Wikipedia.org)
