The best time to visit Quillan for pleasant weather and outdoor activities is from late spring to early autumn, specifically May to September.During these months, you'll experience warm, sunny days superb for exploring the Aude River, cycling through the Quillan countryside, or hiking in the nearby Pyrenees foothills. July and August are the warmest months, with average temperatures often reaching the high 20s Celsius, making them ideal for swimming in the local lakes or enjoying al fresco dining.For those who prefer slightly milder temperatures and fewer crowds, May, June, and September are excellent choices. The weather is still very agreeable, with plenty of sunshine, but the peak summer rush has either not yet begun or has started to subside.