The climate of Salt Lake City is fairly extreme, with a low annual average temperature of around 52°F (11°C), and a high of 90 °F (32.2 °C). Between November and April snow is common, with snowstorms moving in from the Gulf of Alaska. In mid-winter temperature inversions cause pollution and fog to hang in the valley for up to weeks at a time. Spring is the wettest season with numerous rain showers, but summers are generally hot and dry, with occasional monsoons during August and September, which can bring thunderstorms, tornadoes and flash floods. Autumn is also prone to rain, and very variable temperatures.
