Minnesota has a continental climate, with cold, winters and warm summers. The northern counties have about 100 days of growing season while the counties in the south-central and southeastern region have 160 days or more.  Normal daily mean temperatures range from 7°F (–14°C) in January to 66°F (19°C) in July for Duluth, and from 12°F (–11°C) in January to 74°F (23°C) in July for Minneapolis-St. Paul, often called the Twin Cities. Annual precipitation averages 31 in (79 cm) at Duluth and 29.4 in (75 cm) at Minneapolis-St. Paul. Precipitation is lightest in the northwest, where it averages 19 in (48 cm) per year. Blizzards hit Minnesota twice each winter on the average.