The highest day temperature in September 2025 was 90°F. The lowest night temperature was 61°F. The average values for day and night temperatures during September were 75.5°F и 65.2°F respectivly.

The average sea surface temperature in September 2025 for Itanhaem was 71.3°F. The maximum and minimum values were 69.2°F and 74.0°F respectively.

You can expect various weather conditions during September. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in September for Itanhaem is 1.1 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 5.5 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Itanhaem in September is 6.4 hours.