Carcassonne has a hot Mediterranean climate softened by altitude. Summers are dry, sunny, and frequently above 30 °C; the Cité bakes in July and August and the tour buses arrive by the dozen. Winters are mild, with the occasional cold snap from the north.
The best months are May, June, September, and early October: warm enough, light enough, and quiet enough to enjoy the walls properly. 14 July is the great event — Bastille Day fireworks staged from the ramparts, watched from the river bank, with crowds of fifty thousand and more. The Festival de Carcassonne (July) brings opera and concerts to the open-air theatre inside the Cité. Cassoulet weather, on the other hand, is November through February.