September weather forecast
Takamatsu, Japan

The first month of the autumn, September, is also a moderately hot month in Takamatsu, Japan, with an average temperature ranging between max 27.6°C (81.7°F) and min 19.8°C (67.6°F).

Temperature

The transition to September results in a modest reduction in average high-temperature, moving from a tropical 31.7°C (89.1°F) in August to a warm 27.6°C (81.7°F). Throughout the month of September, Takamatsu observes an average nighttime temperature of 19.8°C (67.6°F).

Heat index

Throughout September, the heat index is computed to be a tropical 31°C (87.8°F). Persisting in activity during exposure could lead to weariness and subsequently to heat cramps.
It is worth noting that heat index values are gauged for conditions in the shade and light breezes. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', marries air temperature and humidity to produce a value illustrating perceived warmth. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. Keep it in mind, direct sunlight can augment the heat you experience, possibly pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Youngsters are usually more at risk than adults, considering they sweat less. Additionally, their high skin surface area compared to their little bodies and their high heat production due to activity increases their risk.

Humidity

The months with the highest humidity are July and September, with an average relative humidity of 76%.

Rainfall

The month with the most rainfall is September, when the rain falls for 17 days and typically aggregates up to 187mm (7.36") of precipitation.

Snowfall

In Takamatsu, snow does not fall in March through December.

Sea temperature

In Takamatsu, the average seawater temperature in September is 26.6°C (79.9°F).
Note: Water temperatures between 25°C (77°F) and 29°C (84.2°F) are ideal for all water activities, offering enjoyment without causing discomfort over extended periods.

Daylight

In Takamatsu, the average length of the day in September is 12h and 24min.
On the first day of the month, sunrise is at 05:37 and sunset at 18:30. On the last day of September, in Takamatsu, sunrise is at 05:57 and sunset at 17:49 JST.

Sunshine

The average sunshine in September is 5.2h.

UV index

The average daily maximum UV index in September in Takamatsu is 8. A UV Index estimate of 8 to 10 represents a very high health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: The UV index of 8 in September translates into these instructions:
Always remain cautious. Unprotected skin and eyes are prone to swift harm. Between 10 a.m. and 4 p.m., UV radiation is strongest. Make an effort to avoid direct sunlight during this time, remembering that shade structures may not provide full sun protection. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Notice! The reflection of water and sand increases the UV radiation significantly.