The highest day temperature in October 2025 was 91°F. The lowest night temperature was 62°F. The average values for day and night temperatures during October were 79.3°F и 70.5°F respectivly.

The average sea surface temperature in October 2025 for Niteroi was 75.6°F. The maximum and minimum values were 72.4°F and 78.6°F respectively.

Most of the days in October are gloomy but you can also expect sunny days.

Precipitation total in October for Niteroi is 2.1 in. It makes october one of the most rainy months of the year.

The average wind speed in October is 6.8 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 Niteroi in October is 5.3 hours.