Climate of Dallas  Dallas is located in North Texas , built along the Trinity River. It has a humid subtropical climate (Köppen climate classification: Cfa) that is characteristic of the Southern Plains of the United States. Dallas experiences mild winters and hot summers. Summers are very hot and humid, with temperatures approaching those of desert and semidesert locations of similar latitude. Heat waves can be severe. During the summer, the region receives warm and dry winds from the north and west, as well as hot, humid air from the Gulf of Mexico. The city's all-time recorded high temperature is during the Heat Wave of 1980, while the all-time recorded low is 1899. The average daily low in Dallas is and the average daily high in Dallas is . Dallas receives approximately of equivalent rain per year. Spring and autumn bring pleasant weather to the area. Vibrant wildflowers (such as the bluebonnet, Indian paintbrush and other flora) bloom in spring and are planted around the highways throughout Texas. Springtime weather can be quite volatile, but temperatures themselves are mild. The weather in Dallas is also generally pleasant between late September and early December, and unlike springtime, major storms rarely form in the area. In the spring, cool fronts moving south from Canada collide with warm, humid air streaming in from the Gulf Coast. When these fronts meet over north central Texas, severe thunderstorms are generated with spectacular lightning shows, torrents of rain, hail, and occasionally, tornadoes (Dallas is located at the lower-end of the Tornado Alley). The U.S. Department of Agriculture places Dallas in Plant Hardiness Zone 8a. During the winter season, daytime highs above are not unusual. On the other hand, a couple of times each year, warm and humid air from the south overrides cold, dry air, leading to freezing rain, which often causes major disruptions in the city if the roads and highways become slick. Due to the city's location inland from the Gulf Coast, the city's climate is characterized by a relatively wide annual temperature range, as well as significant weather variations in a given month. There are two to three days with hail per year, but snowfall is rare. Based on records from 1898 to 2019, the average snowfall is 2.6 inches per year. It has snowed twice during Thanksgiving day NFL football games at Texas Stadium, in 1993 and 2007, which is comparatively early. The month with the highest snowfall is typically February, with an average of 0.6 inches falling.