Weather in Bismarck

Planning your day in Bismarck? Check out the latest weather data, detailed forecasts, and illustrative charts presented below.

The climate in Bismarck, North Dakota, USA, is characterised as continental with clearly defined seasons. The city experiences significant temperature fluctuations throughout the year. Winters here are cold, with average monthly temperatures well below freezing, while summers are warm and sometimes hot.

The summer months, especially July and August, bring comfortable warm weather with average temperatures around 20-23°C. Spring and autumn are transitional seasons with more moderate temperatures. One of the characteristic features of Bismarck's climate is the relatively low amount of precipitation throughout the year, with a slight increase in the summer months, but generally remaining at a low level. The number of rainy days is also small, indicating predominantly dry weather.

The annual temperature range in Bismarck is quite extensive: from severe winter frosts to rather hot summers. The coldest months are traditionally January and February, when the average air temperature is around -8.4°C. During these months, night-time temperatures regularly drop significantly below -10°C, averaging -12.8°C in January and -13.8°C in February, while daily highs rarely rise above -3°C. In contrast, the hottest month is July, with an average temperature of +22.9°C and daily peaks reaching +29.0°C. June and August are also distinguished by warm weather, with average temperatures of +20.4°C and +21.7°C respectively.

The summer months in Bismarck, from June to August, offer warm, and at times hot, weather. Daytime temperatures in July often approach the +30°C mark, creating comfortable conditions for various types of summer recreation. Nights in summer also remain warm, with average minimum temperatures ranging from +14.2°C in June to +16.8°C in July. It is worth noting the noticeable diurnal temperature variations: the difference between daily highs and nightly lows can be 10-12 degrees, bringing pleasant coolness in the evening and night hours after the daytime heat.

The winter period, from December to February, is distinguished in Bismarck by stable frosty weather. Average monthly temperatures in January and February hold steady at around -8.4°C, and days when the thermometer does not rise above -3°C even during the day are not uncommon. Night frosts during these months are the norm. The transitional seasons – spring and autumn – are characterised by rapid changes in temperature conditions. For example, while the average temperature in March is still below freezing (-1.6°C), by May it reaches a comfortable +13.7°C. In autumn, the reverse process occurs: from a warm September (+17.6°C) to a cold November, when the average temperature approaches zero (-0.1°C).

In the city of Bismarck, a fairly distinct distribution of precipitation is observed throughout the year, although the total amount remains moderate. The winter months, especially January and February, are the driest. During this period, despite sub-zero temperatures suggesting snowfall, the average amount of measured precipitation is 0 mm. Nevertheless, about 5 "wet days" are registered in each of January and February, which may indicate very light, practically non-accumulating snowfall or frost.

With the arrival of spring, the amount of precipitation gradually increases. March sees about 1 mm of precipitation, likely in the form of snow or sleet, with approximately 6 wet days. April brings 2 mm of precipitation, and the temperature allows for both rain and late snowfalls, with 8 rainy days. May stands out as the month with the highest number of wet days – about 11, with precipitation also amounting to 2 mm, predominantly in the form of rain.

Summer in Bismarck is the "wettest" season in terms of precipitation volume, although even here it is not abundant. June is the month with the maximum average rainfall, reaching 3 mm, which falls over approximately 10 days. In July and August, the amount of precipitation decreases slightly to 2 mm per month, with 9 and 8 rainy days counted respectively. Precipitation during the summer period typically falls as rain.

In autumn, the amount of precipitation declines once again. September sees about 2 mm of precipitation over approximately 6 days. October and November are characterised by 1 mm of precipitation each, with 6 wet days in October, and only 4 in November, making it one of the driest months in terms of precipitation frequency. With the drop in temperature in November, precipitation can be mixed (rain with snow), transitioning to snow by December, when about 1 mm of precipitation falls over 6 days.

When planning a trip to Bismarck, it is important to consider the significant temperature fluctuations throughout the year. In winter (from December to February), it is quite frosty here: the average temperature drops to -8°C, and the minimum can reach -13°C and below. Therefore, at this time of year, you will need very warm clothing: an insulated and preferably windproof jacket or coat, a hat, a scarf, gloves, and waterproof warm boots. Thermal underwear will also be very useful, especially if you plan to spend a lot of time outdoors. Although the monthly amount of precipitation in winter is small (about 0-1 mm), snowy days do occur, so waterproof outerwear will be beneficial.

The summer months (from June to August) in Bismarck are warm, with an average temperature of around 20-23°C, and during the day the thermometer can rise to 29°C. For this season, light clothing is suitable: t-shirts, shorts, dresses, and sandals. Do not forget headwear and sunscreen for protection against the sun. Spring (March-May) and autumn (September-November) are transitional periods with very changeable weather, where the temperature can fluctuate from cool to moderately warm. During this time, it is best to adhere to the principle of layering in your clothing: for example, a t-shirt, a sweater or fleece jacket, and a light jacket, so you can easily adapt to temperature changes throughout the day. Regardless of the season, always take comfortable walking shoes with you. Although the total amount of precipitation in Bismarck is not high (2-3 mm in the wettest months), there are between 4 and 11 days with precipitation in every month, so a compact umbrella or a light raincoat may come in handy.