September weather forecastIruma, Japan
September
Weather in September
The first month of the autumn, September, is still a warm month in Iruma, Japan, with an average temperature varying between 20.5°C (68.9°F) and 27.4°C (81.3°F).Temperature
Transitioning from August to September involves a subtle drop in average high-temperatures, descending from a hot 32°C (89.6°F) to a moderately hot 27.4°C (81.3°F). Iruma records a steady low-temperature average of 20.5°C (68.9°F) during September.Heat index
The heat index value during September is evaluated at a hot 30°C (86°F). Uninterrupted activity during exposure could lead to a sense of exhaustion, possibly causing heat cramps.In the scope of the heat index, its values resonate with shade and light wind conditions. Heat index values might soar by up to 15 Fahrenheit (8 Celsius) degrees with exposure to direct sunshine.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. The impression of weather on a person can be swayed by additional aspects, including metabolic variations, pregnancy, and activity levels. Given direct exposure to sunlight, one might experience a rise in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
Humidity
The average relative humidity in September is 72%.Rainfall
In Iruma, in September, during 14.7 rainfall days, 90mm (3.54") of precipitation is typically accumulated. In Iruma, during the entire year, the rain falls for 146.2 days and collects up to 669mm (26.34") of precipitation.Snowfall
In Iruma, Japan, snow does not fall in April through October and December.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September in Iruma, sunrise is at 05:14 and sunset at 18:10. On the last day of the month, sunrise is at 05:36 and sunset at 17:28 JST.
Sunshine
In Iruma, the average sunshine in September is 7.7h.UV index
In Iruma, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 5 translates into these guidelines:
Ensure safety - Sun damage prevention is strongly urged. Around midday, solar radiation is most harmful; hence, exposure should be limited. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Iruma, Japan
- Average high temperature in September: 27.4°C
The warmest month (with the highest average high temperature) is August (32°C).
The month with the lowest average high temperature is January (8.4°C).
- Average low temperature in September: 20.5°C
The month with the highest average low temperature is August (24.7°C).
The coldest month (with the lowest average low temperature) is January (1.4°C).
Average pressure in September
Iruma, Japan
- Average pressure in September: 1013.7mbar
The month with the highest atmospheric pressure is November (1018.4mbar).
The month with the lowest atmospheric pressure is June (1009.2mbar).
Average wind speed in September
Iruma, Japan
- Average wind speed in September: 9km/h
The windiest month (with the highest average wind speed) is April (11.5km/h).
The calmest month (with the lowest average wind speed) is July (8.7km/h).
Average humidity in September
Iruma, Japan
- Average humidity in September: 72%
The months with the highest relative humidity are June and July (73%).
The month with the lowest relative humidity is January (58%).
Average rainfall in September
Iruma, Japan
- Average rainfall in September: 90mm
The wettest month (with the highest rainfall) is October (102mm).
The driest month (with the least rainfall) is December (21mm).
Average rainfall days in September
Iruma, Japan
- Average rainfall days in September: 14.7 days
The month with the highest number of rainy days is June (18.5 days).
The month with the least rainy days is January (4.8 days).
Average snowfall in September
Iruma, Japan
- Average snowfall in September: 0mm
The month with the highest snowfall is February (39mm).
The months with the least snowfall are April, May, June, July, August, September, October and December (0mm).
Average snowfall days in September
Iruma, Japan
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.1 days).
The months with the least snowfall days are April, May, June, July, August, September, October and December (0 days).
Average daylight in September /
Average sunshine in September
Iruma, Japan
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 7h and 42min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The months with the least sunshine are February and November (Average sunshine: 6h and 12min).
Average sunshine days in September
Iruma, Japan
- Average sunshine days in September: 11.7 days
The month with the most sunshine days is January (25.3 days).
The month with the least sunshine days is June (9.1 days).
Average UV index in September
Iruma, Japan
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in September
Iruma, Japan
- Average cloud cover in September: 42
The month with the most cloud cover is June (Cloud cover 45).
The month with the least cloud cover is January (Cloud cover 26).
Average visibility in September
Iruma, Japan
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, April, May, November and December (10km).
The months with the lowest visibility are June, July, August, September and October (9km).
