September weather forecastIwai, Japan
September
Weather in September
September, the first month of the autumn in Iwai, is still a warm month, with an average temperature varying between 27.2°C (81°F) and 20.5°C (68.9°F).Temperature
September marks a gentle change in average high-temperature, declining from August's tropical 31.9°C (89.4°F) to a moderately hot 27.2°C (81°F). In September, Iwai's temperature tends to fall to an average low of 20.5°C (68.9°F) during the night.Heat index
For September, the heat index is evaluated at a tropical 30°C (86°F). Ongoing activity coupled with exposure often results in weariness and could induce heat cramps.Be advised, the heat index considers values for conditions in shade and with a light breeze. Direct sunlight has the potential to heighten heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a calculation that merges air temperature and relative humidity to depict the sensation of warmth. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Should you be directly under the sun, anticipate a possible increase in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Kids frequently ignore the importance of taking a break and rehydrating. Thirst is a late symptom of dehydration - thus, it is crucial to stay hydrated, especially during long-lasting physical activities.
Humidity
In September, the average relative humidity is 74%.Rainfall
In Iwai, Japan, in September, during 16.5 rainfall days, 111mm (4.37") of precipitation is typically accumulated. Throughout the year, there are 161.3 rainfall days, and 876mm (34.49") of precipitation is accumulated.Snowfall
April through December are months without snowfall in Iwai.Daylight
In Iwai, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 05:12 and sunset at 18:08. On the last day of September, sunrise is at 05:34 and sunset at 17:25 JST.
Sunshine
In Iwai, the average sunshine in September is 7.4h.UV index
In Iwai, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: In September, a daily UV index of 5 turns into the following recommendations:
Take necessary precautions - Defending against sun damage is advocated. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Iwai, Japan
- Average high temperature in September: 27.2°C
The warmest month (with the highest average high temperature) is August (31.9°C).
The month with the lowest average high temperature is January (8.3°C).
- Average low temperature in September: 20.5°C
The month with the highest average low temperature is August (24.4°C).
The coldest month (with the lowest average low temperature) is January (1.7°C).
Average pressure in September
Iwai, Japan
- Average pressure in September: 1013.6mbar
The month with the highest atmospheric pressure is November (1018.2mbar).
The month with the lowest atmospheric pressure is June (1009.2mbar).
Average wind speed in September
Iwai, Japan
- Average wind speed in September: 9.9km/h
The windiest month (with the highest average wind speed) is April (12.3km/h).
The calmest month (with the lowest average wind speed) is November (9.1km/h).
Average humidity in September
Iwai, Japan
- Average humidity in September: 74%
The months with the highest relative humidity are June and July (76%).
The month with the lowest relative humidity is January (60%).
Average rainfall in September
Iwai, Japan
- Average rainfall in September: 111mm
The wettest month (with the highest rainfall) is October (122mm).
The driest month (with the least rainfall) is December (31mm).
Average rainfall days in September
Iwai, Japan
- Average rainfall days in September: 16.5 days
The month with the highest number of rainy days is July (18.7 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in September
Iwai, Japan
- Average snowfall in September: 0mm
The month with the highest snowfall is February (36mm).
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0mm).
Average snowfall days in September
Iwai, Japan
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2 days).
The months with the least snowfall days are April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Iwai, Japan
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 7h and 24min
The month with the most sunshine is August (Average sunshine: 9h and 42min).
The month with the least sunshine is February (Average sunshine: 5h and 42min).
Average sunshine days in September
Iwai, Japan
- Average sunshine days in September: 10.8 days
The month with the most sunshine days is January (23.3 days).
The month with the least sunshine days is June (9.7 days).
Average UV index in September
Iwai, Japan
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Iwai, Japan
- Average cloud cover in September: 44
The month with the most cloud cover is June (Cloud cover 49).
The month with the least cloud cover is January (Cloud cover 29).
Average visibility in September
Iwai, Japan
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, November and December (10km).
The months with the lowest visibility are April, May, June, July, August, September and October (9km).
