The best time to go to Bad Oeynhausen is during the months of May, June, and September. These months offer pleasant weather, ideal for exploring the town and its surroundings without the peak crowds of mid-summer.In May and June, the weather is typically mild and sunny, with temperatures ranging from 15°C to 22°C. This makes it great for enjoying the extensive parks and gardens, such as the Kurpark, which will be in full bloom. It's also a great time for leisurely walks along the River Werre or exploring the local architecture.September also offers agreeable weather, with temperatures generally between 15°C and 20°C, and the summer holiday crowds have dispersed. This is an excellent time for travellers who prefer a more relaxed pace and wish to enjoy the cultural offerings, like the GOP Varieté-Theater, without feeling rushed.