Please answer a question about the following article about Ann Arbor, Michigan:

Ann Arbor has a typically Midwestern humid continental climate (Köppen Dfa), which is influenced by the Great Lakes. There are four distinct seasons: winters are cold with moderate to heavy snowfall, while summers are very warm and humid, and spring and autumn are short but mild. The area experiences lake effect weather, primarily in the form of increased cloudiness during late fall and early winter. The monthly daily average temperature in July is 72.6 °F (22.6 °C), while the same figure for January is 24.5 °F (−4.2 °C). Temperatures reach or exceed 90 °F (32 °C) on 10 days, and drop to or below 0 °F (−18 °C) on 4.6 nights. Precipitation tends to be the heaviest during the summer months, but most frequent during winter. Snowfall, which normally occurs from November to April but occasionally starts in October, averages 58 inches (147 cm) per season. The lowest recorded temperature was −23 °F (−31 °C) on 11 February 1885 and the highest recorded temperature was 105 °F (41 °C) on 24 July 1934.

How many seasons are experienced in the city of Ann Arbor?
four