a humid subtropical climate according to the Köppen classification, with generally hot, humid summers and mild winters by the standards of most of the U.S. Compared to most large cities around the world at approximately the same latitude (33°39'), such as Beirut, Casablanca, Dallas, Los Angeles, and Phoenix, Snellville has lower average winter temperatures. The primary reason for this is that the North American continent extends into high latitudes that allows systems to form and move eastward and southward without obstruction by major mountain ranges. Other factors include Snellville's distance from large bodies of water; its higher elevation, which can lead to rapid weather changes; prevailing wind patterns; and extensive tree cover, which reduces the urban heat island effect (an advantage during summer). In the winter, weather systems sweeping south from Canada, through the Midwest, bring temperatures that can reach below 25 °Fahrenheit (−3.9 °Celsius) a few times a year. The lowest temperature recorded in the city is −9 °F (−22 °C), reached on February 13, 1899. It also reached twice and once in Atlanta in the 1980s and 1990s. An average year sees frost on 48 days; snowfall, which occurs most years, averages 2 inches (5 centimeters) annually. The greatest single accumulation of snow was 10 inches (25 centimeters), on January 23, 1940. A more prominent issue in winter are the frequent ice storms that can cause more problems than snow; the most severe such storm may have occurred on January 7, 1973. Also during winter, warm air sometimes flows from the Gulf of Mexico, raising temperatures as high as 75 °F (24 °C). Though summers are humid, actual temperatures are lower than they may feel, with afternoon highs peaking at about 90 °F (32 °C) in late July. Temperatures rarely reach 100 °F (38 °C), which, during the last 30 years, was recorded in 1980, 1983, 1986, 1993, 1995, 2000, and 2007. The highest temperature recorded in the city is 105 °F (40.6 °C), reached on July 13 and 17, 1980. Like the rest of the Southeastern U.S., the Atlanta metropolitan area experiences abundant rainfall, which is relatively evenly distributed throughout the year. Average annual rainfall is 50.5 inches (127 centimeters); the only other major U.S. cities with greater rainfall are Miami, Florida, and New Orleans, Louisiana. Parks Thomas W. Briscoe Park consists of 87 developed acres (100 total acres), just south of the city center on Lenora