The highest day temperature in January 2026 was 62°F. The lowest night temperature was 41°F. The average values for day and night temperatures during January were 55.5°F и 51.1°F respectivly.

The average sea surface temperature in January 2026 for Posillipo was 61.9°F. The maximum and minimum values were 60.4°F and 63.8°F respectively.

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

Precipitation total in January for Posillipo is 1.7 in. It makes january one of the most rainy months of the year.

The average wind speed in January is 6.5 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 Posillipo in January is 5.2 hours.