September weather forecastHerndon, KS
September
Weather in September
September, the first month of the autumn in Herndon, is still a warm month, with an average temperature ranging between max 81°F (27.2°C) and min 59.7°F (15.4°C).Temperature
As August makes way for September, Herndon's average high-temperature eases from a tropical 89.1°F (31.7°C) to a moderately hot 81°F (27.2°C). During September, Herndon witnesses a consistent average low-temperature of 59.7°F (15.4°C).Heat index
In September, the average heat index is appraised at 82.4°F (28°C). Fatigue might occur with continuous exposure and activity, potentially causing heat cramps.Heat index's context suggests values are appropriate for shady areas and slight breezes. The heat index may experience an enhancement of 15 Fahrenheit (8 Celsius) degrees under direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a calculation that merges air temperature and relative humidity to depict the sensation of warmth. An individual's perception of weather can be affected by a variety of elements including metabolic differences, being pregnant, and their level of physical exertion. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Children often miss understanding the importance of rest and rehydration. Thirst usually appears late during dehydration - therefore, maintaining hydration, particularly during long physical activities, is essential.
Humidity
The average relative humidity in September is 54%.Rainfall
In Herndon, during September, the rain falls for 10.4 days and regularly aggregates up to 1.06" (27mm) of precipitation. In Herndon, during the entire year, the rain falls for 105.3 days and collects up to 15.79" (401mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 7:11 am and sunset at 8:14 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 7:26 pm CDT.
Sunshine
In Herndon, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum UV index, 5 during September, leads to the following recommendations:
Ensure safety - Recommendations to avert sunburn are presented. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Enhance your sun protection with tightly woven, yet airy clothing.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Herndon, KS
- Average high temperature in September: 81°F
The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is December (40.1°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Herndon, KS
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.82"Hg).
Average wind speed in September
Herndon, KS
- Average wind speed in September: 10.7mph
The windiest month (with the highest average wind speed) is April (12.4mph).
The calmest month (with the lowest average wind speed) is August (9.8mph).
Average humidity in September
Herndon, KS
- Average humidity in September: 54%
The month with the highest relative humidity is January (67%).
The month with the lowest relative humidity is July (52%).
Average rainfall in September
Herndon, KS
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in September
Herndon, KS
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is May (14.7 days).
The month with the least rainy days is February (2.6 days).
Average snowfall in September
Herndon, KS
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.17").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Herndon, KS
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (6.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Herndon, KS
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The months with the least sunshine are January and December (Average sunshine: 6h and 18min).
Average sunshine days in September
Herndon, KS
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is November (23.9 days).
The month with the least sunshine days is August (12.9 days).
Average UV index in September
Herndon, KS
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Herndon, KS
- Average cloud cover in September: 21
The month with the most cloud cover is February (Cloud cover 35).
The months with the least cloud cover are June and July (Cloud cover 20).
Average visibility in September
Herndon, KS
- 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).
