September weather forecastAltoona, FL
September
Weather in September
The first month of the autumn, September, is still a tropical month in Altoona, Florida, with an average temperature varying between 88.5°F (31.4°C) and 73.2°F (22.9°C).Temperature
September brings an average high-temperature of a still hot 88.5°F (31.4°C), nearly identical to the preceding month. In Altoona, September nights witness a steady temperature drop to an agreeable 73.2°F (22.9°C).Heat index
The heat index value during September is computed to be a blisteringly hot 105.8°F (41°C). Take extra safety measures to prevent heat exhaustion and heat cramps. Heatstroke could follow lengthy activity.It is emphasized that the heat index's values are meant for shaded zones with mild winds. 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 'felt air temperature', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. Direct sunlight exposure should be noted as it has the potential to increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.
Perspiration is the body's default response to elevated temperatures, as it promotes the evaporation of sweat to achieve cooling. Excessive relative humidity disturbs the body's typical cooling process by reducing evaporation, leading to a decrease in body cooling rate and an increase in the sensation of warmth. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.
Humidity
July through September, with an average relative humidity of 78%, are the most humid months.Rainfall
In Altoona, in September, it is raining for 22.3 days, with typically 4.02" (102mm) of accumulated precipitation. Throughout the year, in Altoona, there are 193.1 rainfall days, and 35.71" (907mm) of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 19min.On the first day of the month, sunrise is at 7:04 am and sunset at 7:47 pm. On the last day of September, in Altoona, sunrise is at 7:19 am and sunset at 7:13 pm EDT.
Sunshine
In Altoona, the average sunshine in September is 8.7h.UV index
In Altoona, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: A maximum UV index of 6 in September translates into the following recommendations:
Incorporate safeguards and honour sun safety principles. Protection from skin and eye damage is obligatory. 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. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Altoona, FL
- Average high temperature in September: 88.5°F
The warmest month (with the highest average high temperature) is August (90.9°F).
The month with the lowest average high temperature is January (67.5°F).
- Average low temperature in September: 73.2°F
The month with the highest average low temperature is August (75.7°F).
The coldest month (with the lowest average low temperature) is January (49.5°F).
Average pressure in September
Altoona, 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
Altoona, FL
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is April (6.4mph).
The calmest month (with the lowest average wind speed) is July (4.5mph).
Average humidity in September
Altoona, FL
- Average humidity in September: 78%
The months with the highest relative humidity are July, August and September (78%).
The month with the lowest relative humidity is March (71%).
Average rainfall in September
Altoona, FL
- Average rainfall in September: 4.02"
The wettest month (with the highest rainfall) is July (5.91").
The driest months (with the least rainfall) are March and November (1.26").
Average rainfall days in September
Altoona, FL
- Average rainfall days in September: 22.3 days
The month with the highest number of rainy days is July (26.9 days).
The month with the least rainy days is January (9.2 days).
Average daylight in September /
Average sunshine in September
Altoona, FL
- Average daylight in September: 12h and 18min
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 42min
The months with the most sunshine are May and July (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 6h and 6min).
Average sunshine days in September
Altoona, FL
- Average sunshine days in September: 5.7 days
The month with the most sunshine days is January (19 days).
The month with the least sunshine days is August (2.1 days).
Average UV index in September
Altoona, 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 4).
Average cloud cover in September
Altoona, FL
- Average cloud cover in September: 32
The months with the most cloud cover are February and December (Cloud cover 37).
The month with the least cloud cover is May (Cloud cover 29).
Average visibility in September
Altoona, 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).





