The highest day temperature in January 2026 was 97°F. The lowest night temperature was 70°F. The average values for day and night temperatures during January were 85.1°F и 75.9°F respectivly.

The average sea surface temperature in January 2026 for Niteroi was 83.9°F. The maximum and minimum values were 80.8°F and 86.0°F respectively.

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

Precipitation total in January for Niteroi is 2.4 in. It makes january one of the most rainy months of the year.

The average wind speed in January is 5.1 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 January is 6.5 hours.