Monaco typically experiences a transition from summer to autumn during this month. Warm, sunny days are still common, with average high temperatures around 24C (75F). Sea temperatures remain pleasant, generally hovering around 22C (72F), making swimming and other water activities enjoyable. However, cooler evenings become more frequent, with average low temperatures dipping to about 18C (64F). Rainfall is possible, though less frequent than in later autumn months.
This period offers a favorable climate for visitors seeking a balance between warm weather and fewer crowds than the peak summer months. The moderate temperatures create ideal conditions for exploring the city-state’s attractions, from the opulent Casino de Monte-Carlo to the serene Jardin Exotique. Historically, September has marked the conclusion of the main tourist season, allowing for a more tranquil experience while still enjoying favorable weather. The transition to autumn also brings a unique ambiance to the region, with the landscape beginning to reflect the changing seasons.