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 in September
- Average snowfall days 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
Heathrow starts September with an average high-temperature of a still hot 88°F (31.1°C), hinting at a minimal fluctuation from August. Heathrow records a mean low-temperature of 74.3°F (23.5°C) in September.Heat index
The heat index value during September is computed to be a blistering 104°F (40°C). Preventive measures are required to mitigate the risk of heat cramps and heat exhaustion. Continuous activity may precipitate heatstroke.Thinking about the heat index, one should account for its values in shaded areas with gentle breezes. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', gives an indication of how one might feel in terms of heat after considering humidity. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. When air moisture content is high, the cooling process through evaporation is not as efficient, leading to an ineffective body cooling process and a feeling of overheating. Overheating risks increase with rising body temperatures, especially if heat release isn't efficient.
Humidity
The months with the highest humidity are August and September, with an average relative humidity of 77%.Rainfall
In Heathrow, in September, it is raining for 20.8 days, with typically 3.46" (88mm) of accumulated precipitation. In Heathrow, during the entire year, the rain falls for 185.5 days and collects up to 30.43" (773mm) of precipitation.Snowfall
February through December are months without snowfall.Daylight
In September, the average length of the day is 12h and 19min.On the first day of the month, sunrise is at 7:03 am and sunset at 7:46 pm. On the last day of September, sunrise is at 7:18 am and sunset at 7:12 pm EDT.
Sunshine
The average sunshine in September is 8.9h.UV index
May through September, with an average maximum UV index of 7, are months with the highest UV index in Heathrow. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum daily UV index, 7 in September, converts into the following recommendations:
Stand by precautions and apply sun safety measures. Evading sunburn is of great importance. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. Experience reduced UV exposure by about half when donning a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the most humid month?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Heathrow have in September?
What time are sunrise and sunset in September?
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
Heathrow, FL
- Average high temperature in September: 88°F
The warmest month (with the highest average high temperature) is August (91°F).
The month with the lowest average high temperature is January (67.8°F).
- Average low temperature in September: 74.3°F
The month with the highest average low temperature is August (76.6°F).
The coldest month (with the lowest average low temperature) is January (52°F).
Average pressure in September
Heathrow, FL
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is September (29.97"Hg).
Average wind speed in September
Heathrow, FL
- Average wind speed in September: 5.2mph
The windiest months (with the highest average wind speed) are January, March and April (6.6mph).
The calmest month (with the lowest average wind speed) is July (4.7mph).
Average humidity in September
Heathrow, FL
- Average humidity in September: 77%
The months with the highest relative humidity are August and September (77%).
The month with the lowest relative humidity is March (70%).
Average rainfall in September
Heathrow, FL
- Average rainfall in September: 3.46"
The wettest month (with the highest rainfall) is August (4.72").
The driest month (with the least rainfall) is March (1.18").
Average rainfall days in September
Heathrow, FL
- Average rainfall days in September: 20.8 days
The month with the highest number of rainy days is August (23.8 days).
The month with the least rainy days is January (10.1 days).
Average snowfall in September
Heathrow, FL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.04").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Heathrow, FL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.1 days).
The months with the least snowfall days are February, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Heathrow, FL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 54min).
The month with the shortest days is December (Average daylight: 10h and 18min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 12min).
Average sunshine days in September
Heathrow, FL
- Average sunshine days in September: 6.6 days
The month with the most sunshine days is January (17.4 days).
The month with the least sunshine days is August (4.3 days).
Average UV index in September
Heathrow, FL
- Average UV index in September: 7
The months with the highest UV index are May, June, July, August and September (UV index 7).
The month with the lowest UV index is January (UV index 4).
Average cloud cover in September
Heathrow, FL
- Average cloud cover in September: 29
The month with the most cloud cover is February (Cloud cover 36).
The month with the least cloud cover is May (Cloud cover 27).
Average visibility in September
Heathrow, 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).
Heathrow, Florida, USA
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