The best time to visit Onís, Asturias, Spain, is during late spring (May to June) and early autumn (September to October) when the weather is pleasant and the natural landscapes are at their most inviting.During these months, you'll experience mild temperatures, making it ideal for outdoor activities like hiking and exploring the Picos de Europa National Park. The spring brings lush greenery and blooming wildflowers, while autumn showcases beautiful fall foliage, creating picturesque scenery for photographers and nature enthusiasts.For those seeking warmer weather and a livelier atmosphere, July and August are also good options, though these months tend to be busier with more tourists.