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 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
The arrival of September is marked by an average high-temperature of a still hot 87.3°F (30.7°C), bearing a close resemblance to August. September records a small disparity from daytime temperatures, marking an average low-temperature of 80.4°F (26.9°C).Heat index
The average heat index in September is evaluated at a fiery hot 98.6°F (37°C). Preventive measures are required to mitigate the risk of heat cramps and heat exhaustion. Continuous activity may precipitate heatstroke.Be advised, the heat index considers values for conditions in shade and with a light breeze. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', gives an indication of how one might feel in terms of heat after considering humidity. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. When exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. 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.
In high temperatures, perspiration kicks in, allowing the human body to cool down through the evaporation of sweat. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. Overheating and dehydration threats arise when heat gain goes beyond what the body can comfortably shed.
Humidity
In September, the average relative humidity is 72%.Rainfall
In North Key Largo, in September, during 26.5 rainfall days, 5.71" (145mm) of precipitation is typically accumulated. In North Key Largo, during the entire year, the rain falls for 225.9 days and collects up to 40.91" (1039mm) of precipitation.Ocean temperature
In North Key Largo, in September, the average water temperature is 85.6°F (29.8°C).Note: In water temperatures ranging between 77°F (25°C) and 84.2°F (29°C), activities such as swimming and diving become highly pleasurable for long durations.
Daylight
The average length of the day in September is 12h and 17min.On the first day of the month, sunrise is at 7:02 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:13 am and sunset at 7:08 pm EDT.
Sunshine
The average sunshine in September is 8.9h.UV index
April through September, with an average maximum UV index of 7, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for the average person.Note: In September, the maximum UV index of 7 translates into these guidelines:
Eschew overexposure. Those with light skin may suffer burns in fewer than 20 minutes. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Warning! Sand and water reflections boost the intensity of UV exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
How much does it rain in September?
What is the water temperature in September?
How many hours of daylight does North Key Largo have in September?
What time are sunrise and sunset in September in North Key Largo?
How long on average sun shines in September?
When is the highest UV index?
What is the UV index reading in September?
Average temperature in September
North Key Largo, FL
- Average high temperature in September: 87.3°F
The warmest month (with the highest average high temperature) is August (88.9°F).
The month with the lowest average high temperature is January (73.9°F).
- Average low temperature in September: 80.4°F
The month with the highest average low temperature is August (81.7°F).
The coldest month (with the lowest average low temperature) is January (63.1°F).
Average pressure in September
North Key Largo, FL
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are September and October (29.94"Hg).
Average wind speed in September
North Key Largo, FL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is March (10.2mph).
The calmest month (with the lowest average wind speed) is July (7.1mph).
Average humidity in September
North Key Largo, FL
- Average humidity in September: 72%
The month with the highest relative humidity is December (75%).
The month with the lowest relative humidity is March (68%).
Average rainfall in September
North Key Largo, FL
- Average rainfall in September: 5.71"
The wettest month (with the highest rainfall) is August (6.77").
The driest month (with the least rainfall) is February (1.14").
Average rainfall days in September
North Key Largo, FL
- Average rainfall days in September: 26.5 days
The month with the highest number of rainy days is August (26.8 days).
The months with the least rainy days are January and February (12.5 days).
Average sea temperature in September
North Key Largo, FL
- Average sea temperature in September: 85.5°F
The best month for swimming (with the highest average sea temperature) is August (86.5°F).
The coldest month (with the lowest average sea temperature) is February (74°F).
Average daylight in September /
Average sunshine in September
North Key Largo, FL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 42min).
The month with the shortest days is December (Average daylight: 10h and 36min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 18min).
Average sunshine days in September
North Key Largo, FL
- Average sunshine days in September: 2.5 days
The month with the most sunshine days is March (14.3 days).
The month with the least sunshine days is August (2.1 days).
Average UV index in September
North Key Largo, FL
- Average UV index in September: 7
The months with the highest UV index are April, May, June, July, August and September (UV index 7).
The month with the lowest UV index is January (UV index 5).
Average cloud cover in September
North Key Largo, FL
- Average cloud cover in September: 30
The month with the most cloud cover is October (Cloud cover 36).
The month with the least cloud cover is April (Cloud cover 26).
Average visibility in September
North Key Largo, FL
- 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).
North Key Largo, Florida, USA
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