Located in the north of Tunisia and on the south-east of the Cap Bon peninsula, Hammamet enjoys a typical Mediterranean climate where the summers are long, hot and dry and the winters are mild with occasional rainfall.

The summer starts in April and lasts as late as November. The summer starts and ends with an average temperature of 20°C and during this time the evenings are very pleasant at an average of 12°C. The temperature in Hammamet rises to 30°C in June, July and August. Rains are scarce – July has never recorded a rainfall.

Though winter lasts only from December to February, it is really cold compared to summer. The temperature during the day is around 16°C and during the nights, it can even drop below freezing point. October is still warm at 20°C in the day time and 18°C at night. This may be called the ‘rainy season’. March and November have sunshine for around six hours per day and January has the minimum at just four hours per day.

Interestingly, the summers in Hammamet are relatively cooler than in the other parts of Tunisia and the winters are warmer. The cool microclimate is due to its position of the Cap Bon Peninsula which stretches out into the sea, encircling Hammamet with water.

Source: http://www.travel-hammamet.com/weather