Best Overall: May to September - Warm weather, long daylight hours, and outdoor activities at their peak.
Copenhagen awakens with blooming tulips in King's Garden and cherry blossoms throughout parks. Temperatures range 8-15°C (46-59°F). Fewer tourists mean shorter lines at attractions. Tivoli Gardens opens for spring season. Easter brings special events. Light jacket necessary, but pleasant for walking and cycling. Hotel prices moderate.
Peak tourist season with temperatures 17-22°C (63-72°F) and up to 17 hours of daylight. Perfect for harbor swimming, beach visits, outdoor dining, and canal tours. Roskilde Festival in July. Street life vibrant with outdoor cafés packed. Book accommodations 2-3 months ahead. Prices highest but atmosphere most lively. Occasional rain pack light rain jacket. Many locals vacation in July, giving city relaxed feel.
Shoulder season offers excellent value with smaller crowds. Temperatures 10-15°C (50-59°F). Fall foliage beautiful in parks. Tivoli's Halloween season (mid-October to early November) enchanting. Museums less crowded. Copenhagen Cultural Night in October offers free entry to 200+ venues. Darker evenings create cozy hygge atmosphere in cafés. Bring layers and waterproof jacket.
Cold and dark with temperatures 0-5°C (32-41°F) and only 7 hours daylight in December. Tivoli's Christmas market (mid-November to early January) transforms park into magical wonderland Copenhagen's winter highlight. January-February quietest and cheapest but many attractions have reduced hours. Ice skating rinks pop up. New Nordic cuisine shines in cozy restaurants. Perfect for museum-hopping and experiencing authentic Danish hygge. Bring warm, waterproof clothing.