September weather forecast and climate
Naples, Italy

A distant view of Mount Vesuvius, from Naples in Italy, with a beautiful blue waterfront
A distant view of Mount Vesuvius, from Naples in Italy, with a beautiful blue waterfront
September, the first month of the autumn, in Naples, is also a moderately hot month, with average temperature varying between 19.5°C (67.1°F) and 25.8°C (78.4°F).

Temperature

In September, the average high-temperature slightly decreases, from a hot 30°C (86°F) in August, to a moderately hot 25.8°C (78.4°F). The average low-temperature, in September, is 19.5°C (67.1°F).

Humidity

In September, the average relative humidity in Naples is 64%.

Rainfall

In Naples, Italy, during 11.5 rainfall days, 45mm (1.77") of precipitation is typically accumulated. Throughout the year, there are 139.4 rainfall days, and 569mm (22.4") of precipitation is accumulated.

Snowfall

In Naples snow does not fall in March through December.

Sea temperature

In Naples, Italy, in September, the average water temperature is 24.8°C (76.6°F).
Note: Depending on a person's sensitivity to cold, with regards to sunshine, wind, and air temperature, a quick swim in 24.8°C (76.6°F) water may be enjoyable. (FYI: The official water temperature required for the Olympic swimming competition is 25°C (77°F) to 28°C (82.4°F).)

Daylight

In Naples, the average length of the day is 12.5h.

Sunshine

In Naples, the average sunshine is 10.9h.

UV index

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to the UV radiation for ordinary individuals.
Note: The average daily UV index of 5 in September transform into the following instructions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What is the temperature in September in Naples?

In September, in Naples, the average high-temperature is 25.8°C (78.4°F), and the average low-temperature is 19.5°C (67.1°F).

What is the average humidity in September in Naples?

In Naples, the average relative humidity in September is 64%.

How much does it rain in Naples in September?

In September, the rain falls for 11.5 days. Throughout September, 45mm (1.77") of precipitation is accumulated.

When it does not snow in Naples?

March through December are months without snowfall in Naples.

How warm is the water in September in Naples?

In Naples, the average seawater temperature in September is 24.8°C (76.6°F). A person's cold intolerance, with sunshine, wind, and air temperature, are essential factors for enjoying swimming in 24.8°C (76.6°F) water.

What is the average length of the day in September in Naples?

In Naples, Italy, the average length of the day in September is 12.5h.

How long on average sun shines in September in Naples?

In Naples, Italy, the average sunshine in September is 10.9h.

How high is the UV index in September in Naples?

The average daily maximum UV index in September in Naples, Italy, is 5. A UV Index of 3 to 5 symbolizes a moderate health threat from unsafe exposure to the Sun's UV rays.
Average temperature in September - Naples, Italy
  • Average high temperature in September: 25.8°C

The warmest month (with the highest average high temperature) is August (30°C).
The month with the lowest average high temperature is January (12.3°C).

  • Average low temperature in September: 19.5°C

The month with the highest average low temperature is August (22.7°C).
The coldest months (with the lowest average low temperature) are January and February (7.8°C).

Average pressure in September - Naples, Italy
  • Average pressure in September: 1015.6mbar

The month with the highest atmospheric pressure is December (1018.4mbar).
The month with the lowest atmospheric pressure is April (1014mbar).

Average wind speed in September - Naples, Italy
  • Average wind speed in September: 10.1km/h

The windiest month (with the highest average wind speed) is February (13.9km/h).
The calmest month (with the lowest average wind speed) is August (8.7km/h).

Average humidity in September - Naples, Italy
  • Average humidity in September: 64%

Months with the highest relative humidity are January and November (73%).
The month with the lowest relative humidity is August (61%).

Average rainfall in September - Naples, Italy
  • Average rainfall in September: 45mm

The wettest month (with the highest rainfall) is November (114mm).
The driest month (with the least rainfall) is August (8mm).

Average rainfall days in September - Naples, Italy
  • Average rainfall days in September: 11.5 days

The month with the highest number of rainy days is January (15.4 days).
Months with the least rainy days are July and August (5.2 days).

Average snowfall in September - Naples, Italy
  • Average snowfall in September: 0mm

Months with the highest snowfall are January and February (2mm).
Months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0mm).

Average snowfall days in September - Naples, Italy
  • Average snowfall days in September: 0 days

Months with the highest number of snowfall days are January and February (0.4 days).
Months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).

Average sea temperature in September - Naples, Italy
  • Average sea temperature in September: 24.8°C

The best month for swimming (with the highest average sea temperature) is August (26°C).
The coldest month (with the lowest average sea temperature) is February (13.9°C).

Average daylight in September / Average sunshine in September - Naples, Italy
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.1h).
The month with the shortest days is December (Average daylight: 9.3h).

  • Average sunshine in September: 10.9h

The month with the most sunshine is July (Average sunshine: 12.1h).
The month with the least sunshine is January (Average sunshine: 5.6h).

Average sunshine days in September - Naples, Italy
  • Average sunshine days in September: 15.6 days

The month with the most sunshine days is July (24 days).
The month with the least sunshine days is February (11.1 days).

Average UV index in September - Naples, Italy
  • Average UV index in September: 5

The month with the highest UV index is July (UV index 7).
Months with the lowest UV index are January, February and December (UV index 3).

Average cloud cover in September - Naples, Italy
  • Average cloud cover in September: 19

The month with the most cloud cover is January (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 9).

Average visibility in September - Naples, Italy
  • Average visibility in September: 10km

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).