Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
Temperature readings reach their annual highs in September, averaging 81°F (27.2°C) and a minimum average of 77.4°F (25.2°C).Heat index
For September, the heat index is computed to be a hot 86°F (30°C). Uninterrupted exposure and activity might result in fatigue, potentially causing heat cramps.It is crucial to understand that heat index figures are for shade and gentle wind conditions. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is found by incorporating humidity levels into the air temperature measurement. This effect is personal, shaped by the individual's physical activity and heat sensitivity, influenced by factors including wind, clothing, and metabolic variances. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
Humidity
In Lanai City, the average relative humidity in September is 74%.Rainfall
In Lanai City, in September, it is raining for 7.1 days, with typically 0.43" (11mm) of accumulated precipitation. Throughout the year, there are 98.9 rainfall days, and 7.64" (194mm) of precipitation is accumulated.Snowfall
The only month with snowfall is September. The month with the most snowfall days is September, when snow falls for 0.1 days.Ocean temperature
September and October, with an average ocean temperature of 80.6°F (27°C), are months with the warmest seawater.Note: For swimming, diving, and enjoying other water activities, the range of 77°F (25°C) to 84.2°F (29°C) in water temperature is considered ideal, offering pleasure for extended periods without discomfort.
Daylight
In Lanai City, the average length of the day in September is 12h and 15min.On the first day of the month, sunrise is at 6:11 am and sunset at 6:43 pm. On the last day of September, sunrise is at 6:18 am and sunset at 6:16 pm HST.
Sunshine
In Lanai City, the average sunshine in September is 9.8h.UV index
The months with the highest UV index are May through October, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for the ordinary person.Note: The daily maximum UV index of 7 in September interprets into the following advice:
Stick with precautions and abide by sun safety procedures. Evading sunburn is essential. Avoid exposure to the Sun and try to stay in the shade between 10 a.m. and 4 p.m., when UV radiation is most potent, but be aware that parasols or canopies may not offer full protection. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the hottest?
What is the average September temperature?
What is the average humidity in September?
How many days does it rain in September?
What is the snowiest month?
When does it start to snow?
When is the ocean warmest?
What is the ocean temperature in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the month with the highest UV index?
What is the UV index intensity in September in Lanai City?
Average temperature in September
Lanai City, HI
- Average high temperature in September: 81°F
The warmest month (with the highest average high temperature) is September (81°F).
The month with the lowest average high temperature is February (74.8°F).
- Average low temperature in September: 77.4°F
The months with the highest average low temperature are August and October (77.5°F).
The coldest month (with the lowest average low temperature) is March (71.6°F).
Average pressure in September
Lanai City, HI
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is April (30.05"Hg).
The month with the lowest atmospheric pressure is October (29.96"Hg).
Average wind speed in September
Lanai City, HI
- Average wind speed in September: 9.7mph
The windiest months (with the highest average wind speed) are March and November (10.9mph).
The calmest month (with the lowest average wind speed) is October (9mph).
Average humidity in September
Lanai City, HI
- Average humidity in September: 74%
The month with the highest relative humidity is July (75%).
The months with the lowest relative humidity are January and November (73%).
Average rainfall in September
Lanai City, HI
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is March (1.26").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in September
Lanai City, HI
- Average rainfall days in September: 7.1 days
The month with the highest number of rainy days is March (12.7 days).
The month with the least rainy days is July (4.7 days).
Average snowfall days in September
Lanai City, HI
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is September (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, October, November and December (0 days).
Average sea temperature in September
Lanai City, HI
- Average sea temperature in September: 81°F
The best months for swimming (with the highest average sea temperature) are September and October (81°F).
The coldest months (with the lowest average sea temperature) are January, February, March and April (75°F).
Average daylight in September /
Average sunshine in September
Lanai City, HI
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 24min).
The month with the shortest days is December (Average daylight: 10h and 54min).
- Average sunshine in September: 9h and 5min
The month with the most sunshine is June (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 7h and 6min).
Average sunshine days in September
Lanai City, HI
- Average sunshine days in September: 21.5 days
The month with the most sunshine days is July (25.6 days).
The month with the least sunshine days is February (12.7 days).
Average UV index in September
Lanai City, HI
- Average UV index in September: 7
The months with the highest UV index are May, June, July, August, September and October (UV index 7).
The months with the lowest UV index are January, February, March, April, November and December (UV index 6).
Average cloud cover in September
Lanai City, HI
- Average cloud cover in September: 18
The month with the most cloud cover is March (Cloud cover 27).
The month with the least cloud cover is September (Cloud cover 18).
Average visibility in September
Lanai City, HI
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Lanai City, Hawaii, USA
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