Duluth's winters are harsh, with temperatures often below freezing, averaging around -6°C in January and plummeting as low as -31°C in February. Spring arrives slowly, with March temperatures still quite chilly but warming up by April, which sees averages around 4°C. Summers are mild, with July and August experiencing average highs of around 20°C, while September brings a slight cooling trend. Autumn is cool and crisp, with October temperatures averaging around 11°C before dropping back down into winter. Overall, Duluth's climate is characterized by cold winters and mild summers, with spring and autumn serving as transitional periods.