Bismarck in May

May weather, activities, events & insider tips

May Weather in Bismarck

21°C (70°F) High Temp

7°C (45°F) Low Temp

46 mm (1.8 inches) Rainfall

50% Humidity

Is May Right for You?

Advantages

Perfect outdoor weather - warm days averaging 21°C (70°F) make it ideal for Missouri River activities and hiking without summer's oppressive heat and humidity
Spring migration peak brings 200+ bird species to the Missouri River corridor, making it North Dakota's premier birding month with warblers, pelicans, and waterfowl easily spotted
Lowest tourist crowds of the warm season - attractions like Fort Abraham Lincoln are accessible without summer crowds, and restaurant reservations are easy to secure
Prairie wildflowers in full bloom across the surrounding grasslands create spectacular photography opportunities, especially along the Lewis & Clark Trail

Considerations

Unpredictable weather swings - temperatures can drop 15°C (27°F) in hours when cold fronts move through, requiring layers and flexible outdoor plans
Spring rain showers on 10 days throughout the month can disrupt outdoor activities, though most last only 30-60 minutes
Some seasonal businesses and tour operators haven't fully opened yet, limiting options compared to peak summer months

Best Activities in May

Missouri River Birding and Wildlife Tours

May is peak spring migration when over 200 bird species pass through the Missouri River corridor. Morning temperatures of 10-15°C (50-59°F) are perfect for wildlife activity. Pelicans, great blue herons, and dozens of warbler species are easily spotted. The mild weather means comfortable 2-3 hour excursions without summer heat.

Booking Tip: Book through local naturalist guides 7-10 days ahead (typically $45-75 per person). Early morning tours (6-9am) offer best wildlife viewing. Look for guides certified by the North Dakota Birding Society. See current tour options in the booking section below.

Fort Abraham Lincoln Historical Experiences

May's mild 21°C (70°F) days are perfect for exploring this reconstructed cavalry fort and Mandan village without summer crowds. The fort's living history demonstrations run on weekends, and the 3.2 km (2-mile) hiking trails are comfortable in spring weather. Prairie grasses are green and wildflowers bloom around the earthlodges.

Booking Tip: Self-guided visits cost $7-12 per adult. Guided historical tours typically $25-35 per person, available weekends starting mid-May. Book specialized archeology tours 2 weeks ahead. Current tour availability in booking section below.

Lewis and Clark Riverboat Cruises

May marks the start of riverboat season with comfortable temperatures and high water levels from spring runoff. 2-3 hour cruises along the Missouri River offer perfect weather for deck viewing - warm enough at 21°C (70°F) but not the scorching heat of summer. Spring wildlife is active along the riverbanks.

Booking Tip: Season typically begins mid-May weather permitting. Dinner cruises $35-55, sightseeing cruises $20-30. Weekend slots fill quickly - book 10-14 days ahead. Look for operators with enclosed areas for cool evening temperatures. See current cruise schedules in booking section below.

Prairie Heritage Trail Cycling

May offers ideal cycling weather with mild temperatures and minimal wind compared to summer. The 30+ km network of paved trails connects parks, historical sites, and the riverfront. Morning rides at 7-12°C (45-54°F) are crisp and comfortable, while afternoon temperatures reach perfect cycling conditions.

Booking Tip: Bike rentals typically $25-40 per day from local outfitters. Multi-day packages $60-100. The trails are free to use. Book rental bikes 3-5 days ahead for weekends. Look for shops offering trail maps and weather-appropriate gear recommendations.

Dakota Zoo Spring Animal Encounters

Animals are most active in May's comfortable temperatures before summer heat. Many exhibits that close in winter reopen, and spring babies are often visible. The zoo's 12-hectare grounds are walkable in mild weather, and outdoor shows resume. Prairie dog exhibit is particularly active in spring temperatures.

Booking Tip: Admission $8-15 depending on age. Special animal encounter experiences $15-25 per person. Educational programs book up quickly for school groups - reserve weekend spots 1-2 weeks ahead. See current programming in booking section below.

Sertoma Riverside Park Festivals and Events

May weather is perfect for the park's outdoor event season launch. The 35-hectare park along the Missouri River hosts spring festivals, and the Tashkent is at its most beautiful. Walking paths total 5 km (3.1 miles) and are comfortable in mild spring temperatures.

Booking Tip: Park access is free. Special events typically $5-20 admission. Food vendors and craft booths vary by event. Check the city's event calendar - many festivals are weather-dependent and may reschedule for rain. Current events listed in booking section below.

May Events & Festivals

Mid to Late May

Spring Migration Bird Festival

Local birding groups organize guided walks and educational programs during peak migration. Features early morning birding expeditions along the Missouri River and identification workshops for beginners.

Third weekend in May

Opening Weekend at Fort Abraham Lincoln

The fort's seasonal programming launches with special demonstrations, cavalry drills, and living history presentations. First full weekend of interpretive programming after winter closure.

Essential Tips

What to Pack

Layered clothing system - temperatures swing 15°C (27°F) between morning lows of 7°C (45°F) and afternoon highs of 21°C (70°F)

Light waterproof jacket - spring showers occur on 10 days and can start suddenly, though most last under an hour

Comfortable walking shoes with good traction - trails may have muddy spots from spring runoff and recent rain

SPF 30+ sunscreen - UV index reaches 6 and prairie sun reflects off the Missouri River with little shade

Binoculars - spring migration brings exceptional wildlife viewing opportunities along the river corridor

Light fleece or sweater - evening temperatures drop to 7°C (45°F) and river breezes feel cooler

Baseball cap or sun hat - prairie winds and open skies mean strong sun exposure during midday hours

Insect repellent - mosquitoes emerge near the river as temperatures warm, especially after rain

Windbreaker - prairie winds can be persistent, making actual temperatures feel 3-5°C (5-9°F) cooler

Day pack for outdoor activities - you'll want to carry layers as weather changes throughout the day

Insider Knowledge

The Missouri River is 1.5 meters (5 feet) higher in May due to spring runoff from mountain snowmelt, making it the best month for riverboat cruises and water-based activities

Local restaurants and bars have the freshest walleye and northern pike in May as fishing season opens - many establishments feature 'spring catch' specials not available other times of year

Download the eBird app before visiting - Bismarck is on the Central Flyway migration route and you can see real-time bird sightings from other visitors to plan your birding locations

The State Capitol building offers free tours year-round, but May is ideal because the 19th-floor observation deck provides comfortable viewing of spring prairie colors without winter weather or summer haze

Avoid These Mistakes

Underdressing for morning activities - 7°C (45°F) dawn temperatures require warm layers even when afternoon reaches 21°C (70°F)

Not checking Missouri River water levels before booking boat tours - spring flooding can occasionally cancel river activities with short notice

Assuming summer operating hours - many attractions have limited May schedules as they transition from winter closure to full summer programming