September weather forecast
Merritt Island, FL

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Weather in September

September, the first month of the autumn in Merritt Island, is still a warm month, with an average temperature fluctuating between 85.1°F (29.5°C) and 77.7°F (25.4°C).

Temperature

Transitioning into September, Merritt Island records an average high-temperature of a moderately hot 85.1°F (29.5°C), almost identical to August's 87.3°F (30.7°C). September nighttime temperatures hover close to the daytime peak with an average of 77.7°F (25.4°C).

Heat index

September's average heat index is calculated to be a torrid 95°F (35°C). Implement more preventive measures, heat cramps and heat exhaustion are probable. Heatstroke might result from extended activity.
Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. The direct sunshine could escalate the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', integrates the air's temperature and its humidity to showcase the felt temperature by people. This impact is subjective, influenced by the person's physical activity and individual heat perception, affected by factors including wind, attire, and metabolic differences. When you're directly under the sun's rays, remember that the heat index may surge by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. When relative humidity increases, the body's capacity to evaporate heat decreases, leading to a heightened sense of warmth. When body heat isn't effectively managed, risks of dehydration and overheating amplify.

Humidity

The average relative humidity in September is 77%.

Rainfall

In Merritt Island, during September, the rain falls for 22.5 days and regularly aggregates up to 3.58" (91mm) of precipitation. Throughout the year, there are 190.9 rainfall days, and 29.37" (746mm) of precipitation is accumulated.

Daylight

In September, the average length of the day is 12h and 19min.
On the first day of the month, sunrise is at 7:01 am and sunset at 7:43 pm. On the last day of September, sunrise is at 7:15 am and sunset at 7:09 pm EDT.

Sunshine

The average sunshine in September is 9h.

UV index

May through September, with an average maximum UV index of 7, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 7 in September interprets into the following recommendations:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.

Frequently asked questions

How hot is September?

In Merritt Island, in September, the average high-temperature is 85.1°F (29.5°C), and the average low-temperature is 77.7°F (25.4°C). In September, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which represents the influence of relative humidity on air temperature, is calculated to be 95°F (35°C).

What is the average humidity in September?

In September, the average relative humidity is 77%.

How many days does it rain in September?

In Merritt Island, in September, during 22.5 rainfall days, 3.58" (91mm) of precipitation is typically accumulated.

How many hours of daylight does Merritt Island have in September?

In September, the average day length is 12h and 19min.

When are sunrise and sunset in September?

On the first day of September in Merritt Island, sunrise is at 7:01 am and sunset at 7:43 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:09 pm EDT.

How many hours of sunshine does Merritt Island have in September?

In Merritt Island, the average sunshine duration in September is 9h.

What are the months with the highest UV index?

May through September, with an average maximum UV index of 7, are months with the highest UV index.

What is the UV index reading in September?

In Merritt Island, the average daily maximum UV index in September is 7. A UV Index value of 6 to 7 symbolizes a high health threat from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Merritt Island, FL

Average temperature in September - Merritt Island, FL
  • Average high temperature in September: 85.1°F

The warmest month (with the highest average high temperature) is August (87.3°F).
The month with the lowest average high temperature is January (68.4°F).

  • Average low temperature in September: 77.7°F

The month with the highest average low temperature is August (78.6°F).
The coldest month (with the lowest average low temperature) is January (57.7°F).

Average pressure in September
Merritt Island, FL

Average pressure in September - Merritt Island, FL
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.97"Hg).

Average wind speed in September
Merritt Island, FL

Average wind speed in September - Merritt Island, FL
  • Average wind speed in September: 7.9mph

The windiest months (with the highest average wind speed) are January and November (10mph).
The calmest month (with the lowest average wind speed) is July (6.9mph).

Average humidity in September
Merritt Island, FL

Average humidity in September - Merritt Island, FL
  • Average humidity in September: 77%

The month with the highest relative humidity is August (79%).
The month with the lowest relative humidity is March (72%).

Average rainfall in September
Merritt Island, FL

Average rainfall in September - Merritt Island, FL
  • Average rainfall in September: 3.58"

The wettest month (with the highest rainfall) is August (5.12").
The driest month (with the least rainfall) is March (1.14").

Average rainfall days in September
Merritt Island, FL

Average rainfall days in September - Merritt Island, FL
  • Average rainfall days in September: 22.5 days

The month with the highest number of rainy days is August (24.7 days).
The month with the least rainy days is February (9.6 days).

Average daylight in September /
Average sunshine in September
Merritt Island, FL

Average daylight in September / Average sunshine in September - Merritt Island, 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 24min).

  • Average sunshine in September: 9h and 0min

The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is January (Average sunshine: 6h and 6min).

Average sunshine days in September
Merritt Island, FL

Average sunshine days in September - Merritt Island, FL
  • Average sunshine days in September: 5.3 days

The month with the most sunshine days is January (17.2 days).
The month with the least sunshine days is August (3.1 days).

Average UV index in September
Merritt Island, FL

Average UV index in September - Merritt Island, 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
Merritt Island, FL

Average cloud cover in September - Merritt Island, FL
  • Average cloud cover in September: 28

The months with the most cloud cover are January, November and December (Cloud cover 34).
The months with the least cloud cover are April, May and July (Cloud cover 26).

Average visibility in September
Merritt Island, FL

Average visibility in September - Merritt Island, 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).

Merritt Island, Florida, USA

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