The best time to visit Narbonne is spring (April to June) or early autumn (September to October), when temperatures are warm but not oppressive and the crowds are manageable. July and August are hot — regularly above 35°C — and the city fills with visitors heading to the nearby beaches. The market and restaurants are at their best in summer for produce, but it is not the most comfortable time to walk around.
Winters are mild by northern European standards, with temperatures rarely dropping below 5°C, and the city functions normally year-round. The Fête de la Saint-Georges in April and the jazz festivals in summer are worth timing a visit around if you happen to be passing through.