Climate and monthly weather forecastDuluth, MN

The climate of Duluth

Duluth, Minnesota, USA, bears a Dfb climate classification in the Köppen system. This indicates a humid continental climate with no dry season and a warm summer. Geographically placed in the northern region of the United States, this city is susceptible to a variety of weather conditions throughout the year.

Beginning with temperature, Duluth sees a clear curve throughout the year. Lower temperatures are prevalent from December to February, with the lowest averages falling to 3.9°F (-15.6°C) in January and rising to 21.4°F (-5.9°C) in March. By contrast, the warmer months from June to August record higher temperatures, averaging between 70.3°F (21.3°C) and 75.7°F (24.3°C).

Relative humidity maintains a steady presence all year round, varying slightly from 72% in May to 91% in January. Rainfall is scattered throughout the year, significantly increasing during the spring and early summer, peaking at 3.03" (77mm) in July. Moreover, the city experiences snowfall heavily in the colder months, with January reporting the highest snowfall at 7.72" (196mm).

Uniquely, the sea temperature remains consistently cold, only slightly warming up from 36°F (2.2°C) in most winter and early spring months to a maximum of 61°F (16.1°C) in late summer. Similarly, the daylight hours in Duluth fluctuate between a low of 8.6 hours in December to a high of 15.8 hours in June which is complemented by the measurable increase in sunshine hours from 2.8 hours in January to 10 hours in July. As for atmospheric conditions, the city reports slightly higher pressure levels in the colder months, averaging at 30.09" (764mm).

Storm chasers may be intrigued by the wind speeds in Duluth; the maximum wind speeds per month peak at 9.3mph (15km/h) in October, while gusts can reach up to 13.2mph (21.2km/h) during the same month.

The best time to visit Duluth

The prime time to explore Duluth falls in the warmer months, particularly between June and September. During this period, the average high temperatures fluctuate around a pleasant 70°F (21.1°C), coupled with typically lower rainfall levels. The daily sunshine duration ranges from 8.3 to 10 hours, allowing ample daylight for outdoor activities.

The worst time to visit Duluth

On the flip side, the onset of winter, primarily from December through to February, can be perceived as the least desirable time to visit Duluth, especially for those not accustomed to frigid temperatures. The high levels of snowfall, frequently exceeding 5" (127mm) in January and February, and average low temperatures ranging between 3.9°F (-15.6°C) to 11.8°F (-11.2°C) can pose challenges for outdoor exploration.

Spring weather in Duluth

As Duluth transitions from winter to spring, the city witnesses a noticeable rise in temperature. From a low of 21.4°F (-5.9°C) in March, the mercury level jumps to 46°F (7.8°C) in April. Evenings remain chilly with temperatures as low as 31.3°F (-0.4°C) in April. Moisture levels also see a hike during these months, with rainfall increasing from 1.54" (39mm) in March to an elevated level of approximately 2.52" (64mm) in April.

Summer weather in Duluth

Summertime in Duluth is a blend of warm and wet conditions. With high temperatures soaring to 77.4°F (25.2°C) in July and staying above 70°F (21.1°C) until September, the weather allows for a variety of outdoor activities. Rainfall reaches its yearly peak during these months, maxing out at 3.03" (77mm) in July, and the increased humidity hovering in the mid-70% range can make the air feel muggy.

Autumn weather in Duluth

Fall ushers in a cooling trend, bringing an end to the warm and wet summer. By October, the high temperature drops to 51.3°F (10.7°C) and plunges further to 36.1°F (2.3°C) by November. The rainfall also reduces significantly, recording an average of 2.36" (60mm) in October and dropping to 1.22" (31mm) in November.

Winter weather in Duluth

Winter is synonymous with harsh and chilly conditions in Duluth. With high temperatures barely rising above the freezing point and dipping further to an average low of 11.8°F (-11.2°C) by December, it is a stark change from the milder seasons. Correspondingly, the city sees substantial snowfall, as high as 7.72" (196mm) in December, turning the city into a frosty landscape. Hence, these months are suitable for those who have a penchant for winter sports or enjoy the cold and snowy ambience.

Weather in January

January in Duluth, Minnesota, exhibits the rigors of winter, endowed with copious amounts of snowfall. The chilly weather continues from the latter weeks of the previous year, the mercury seldom rising above the freezing point. Weather in January »

Weather in February

The second month of the year records somewhat milder weather conditions, a sure sign of the impending spring. Despite these enhancements, February can still be considered a winter month, with the cold weather even affecting the sea temperature. Weather in February »

Weather in March

As residents of Duluth transition from winter to spring, March brings forth an upturn in the weather. The chilly temperatures begin to thaw, with the days getting longer and brighter. There is a notable decrease in snowfall days from February's 18.1 to March's 13.3. Weather in March »

Weather in April

April marks the full arrival of spring in Duluth, which signals bud break and bird migration. Increasing temperatures, longer daylight hours, and dwindling snowfall characterize this month. Overcast features give way to clearer skies, boosting the visibility for outdoor activities. Weather in April »

Weather in May

May offers an overt change in Duluth's weather, inciting residents to welcome the onset of summer. The city benefits from warmer temperatures, copious amounts of sunshine, and minimal snowfall. Adding to the favorable weather, the daily hours of sunshine increase, significantly brightening the city. Weather in May »

Weather in June

Summer invades Duluth in June, with the month known for sultry weather, lesser cloud coverage, and longer daylight hours. June becomes a favorite among residents and tourists for outdoor excursions, thanks to its advantageous weather conditions. Weather in June »

Weather in July

July stands as the climatic culmination of summer in Duluth, characterized by the year's hottest temperatures and longest hours of sunshine. The city basks in warm weather, paving the way for a myriad of outdoor activities. This period's warm, comforting temperatures also cause a considerable surge in sea temperature. Weather in July »

Weather in August

August in Duluth holds onto the summer weather, even though the temperatures show a slight decline from the previous month. The month signals the end of the warmest time of the year, preparing for a transition toward the cooler autumn temperatures. Weather in August »

Weather in September

September acts as a harbinger of autumn in Duluth, minor reductions in temperature, daylight hours, and sea temperature distinguish this month. This period is characterized by frequent weather changes and an upsurge in rainfall. Weather in September »

Weather in October

October in Duluth ushers in a more pronounced autumn chill, necessitating warmer clothing. Residents anticipate the city's vibrant foliage during this month, a clear departure from the previous green summer months. As the weather becomes colder, the sea temperature likewise follows suit. Weather in October »

Weather in November

November introduces Duluth to winter weather, with decreasing daylight, a surge in snowfall, and lowering temperatures. The city, moving steadfast into the colder season, witnesses the first heavy spells of snow. Accompanied by an upturn in humidity, conditions become ideal for snow production. Weather in November »

Weather in December

December endures the peak of the winter season in Duluth, characterized by icy winds, copious snowfall, and minimal sunlight. Though officially the start of winter, the city experiences cold weather that sets new low-temperature records. Weather in December »