San Juan Weather in September

In San Juan, September brings very high daytime temperatures around 31°C (88°F), with nights cooling to 25°C (77°F). It is the wettest month of the year, so expect more rainfall than usual.

Rainfall in San Juan in September

This month is known for its intense rain, often falling heavily. Having a poncho will help you stay dry during the showers. Past climate data indicates that roughly 18 days will see rain, totalling around 159 mm (6.3 in) for the month. Rain falls regularly this month and can be quite heavy when it does. Showers can be substantial, so waterproof gear is a good idea.

Temperature in San Juan in September

In September, expect very high temperatures in San Juan, with highs of 31°C (88°F) and lows of 25°C (77°F) at night. If you're spending a lot of time outdoors, it helps to plan around the warmer part of the day. Nights are warm at 25°C (77°F). It's worth making sure your accommodation has decent ventilation or air conditioning.

Sunshine in San Juan in September

The city usually sees around 236 hours of sunlight, indicating many sunny days , a great month for sightseeing.

Wind Speed in San Juan in September

Average wind speeds reach 3 m/s (6 knots) in September, creating light breezes that feel pleasant throughout the day. Some days are calmer, while others bring slightly more active breezes.

Average water temperature in September

The water is 29°C (84°F), very warm by most standards. Comfortable to swim in, but not particularly refreshing if you're looking to cool off.

September in San Juan can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.