September weather forecast
Nagoya, Japan

September, the first month of the autumn, in Nagoya, is also a moderately hot month, with average temperature fluctuating between 20.7°C (69.3°F) and 28.6°C (83.5°F).

Temperature

In September, the average high-temperature marginally drops, from a tropical 32.8°C (91°F) in August, to a warm 28.6°C (83.5°F). The average low-temperature, in Nagoya, is 20.7°C (69.3°F).

Heat index

In September, the average heat index is calculated to be a hot 32°C (89.6°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'real feel', 'feels like', or 'felt air temperature', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. This effect is individual, with diverse people perceiving weather differently for numerous reasons (metabolic differences, differences in body mass, height, and shape, pregnancy), and activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

The average relative humidity in Nagoya is 71%.

Rainfall

The month with the most rainfall in Nagoya is September when the rain falls for 11.9 days and typically aggregates up to 234.4mm (9.23") of precipitation.

Snowfall

In Nagoya snow does not fall in March through November.

Sea temperature

In September, the average sea temperature is 27°C (80.6°F).
Note: For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

In Nagoya, the average length of the day in September is 12.4h.

Sunshine

June and September, with an average of 5h of sunshine, are months with the least sunshine in Nagoya.

UV index

The average daily maximum UV index in September is 8. A UV Index value of 8 to 10 symbolizes a very high health risk from unsafe exposure to the UV radiation for average individuals.
Note: In September, the average maximum UV index of 8 translate into the following recommendations:
Take special precautions, as unprotected eyes and skin can be burned and damaged quickly. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. 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.