The highest day temperature in September 2025 was 86°F. The lowest night temperature was 72°F. The average values for day and night temperatures during September were 78.3°F и 76.0°F respectivly.

The average sea surface temperature in September 2025 for Arenas del Mar was 77.7°F. The maximum and minimum values were 76.6°F and 78.4°F respectively.

Most of the days in September are sunny but you can also expect cloudy and gloomy days.

Precipitation total in September for Arenas del Mar is 0.3 in. This value is relatively stable throughout the year.

The average wind speed in September is 8.6 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 Arenas del Mar in September is 10.4 hours.