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 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 brings an average high-temperature of a still tropical 87.8°F (31°C), nearly identical to August's 91.2°F (32.9°C). The average low-temperature in O'Brien during September nights is an agreeable 70.9°F (21.6°C).Heat index
The heat index in September is estimated at an extremely hot 104°F (40°C). Undertake additional precautions, heat cramps and heat exhaustion could happen. Heatstroke could occur from sustained activity.Thinking about the heat index, one should account for its values in shaded areas with gentle breezes. Exposure to unobstructed sunshine could lead to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', quantifies the warmth felt when relative humidity is considered. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Children often fail to understand the importance of rest and rehydration. Thirst is a late manifestation of dehydration - hence, it is crucial to stay hydrated, especially during ongoing physical activities.
Sweat evaporation plays a crucial role in cooling the human body, a process enabled by perspiration. When relative humidity is heightened, it slows the rate of evaporation, thereby decreasing the body's ability to shed heat and creating a sensation of overheating. Overheating and dehydration threats arise when heat gain goes beyond what the body can comfortably shed.
Humidity
August and September, with an average relative humidity of 77%, are the most humid months.Rainfall
In O'Brien, in September, it is raining for 19.6 days, with typically 3.7" (94mm) of accumulated precipitation. Throughout the year, in O'Brien, Florida, there are 173.7 rainfall days, and 30.83" (783mm) of precipitation is accumulated.Snowfall
In O'Brien, snow does not fall in January, March through December.Daylight
In O'Brien, the average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 7:09 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:18 pm EDT.
Sunshine
The average sunshine in September in O'Brien is 8.3h.UV index
The average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 6 during September leads to these advisories:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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 in O'Brien?
How much does it rain in September?
When it does not snow?
How many hours of daylight does O'Brien have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
O'Brien, FL
- Average high temperature in September: 87.8°F
The warmest months (with the highest average high temperature) are July and August (91.2°F).
The month with the lowest average high temperature is January (62.2°F).
- Average low temperature in September: 70.9°F
The month with the highest average low temperature is August (74.8°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).
Average pressure in September
O'Brien, FL
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.98"Hg).
Average wind speed in September
O'Brien, FL
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is April (6.5mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in September
O'Brien, 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 May (70%).
Average rainfall in September
O'Brien, FL
- Average rainfall in September: 3.7"
The wettest month (with the highest rainfall) is August (4.53").
The driest month (with the least rainfall) is November (0.98").
Average rainfall days in September
O'Brien, FL
- Average rainfall days in September: 19.6 days
The month with the highest number of rainy days is August (25.4 days).
The month with the least rainy days is November (7.1 days).
Average snowfall days in September
O'Brien, FL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
O'Brien, FL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 0min).
The month with the shortest days is December (Average daylight: 10h and 18min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in September
O'Brien, FL
- Average sunshine days in September: 8.8 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is August (4.2 days).
Average UV index in September
O'Brien, FL
- Average UV index in September: 6
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover in September
O'Brien, FL
- Average cloud cover in September: 36
The month with the most cloud cover is December (Cloud cover 40).
The months with the least cloud cover are May and October (Cloud cover 30).
Average visibility in September
O'Brien, FL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is December (5mi).
O'Brien, Florida, USA
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