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
Start of September brings a slight shift in the average high-temperature, dipping a bit from August's hot 86.7°F (30.4°C) to a warm 81.1°F (27.3°C). Throughout September, Rockville witnesses a nighttime temperature average of 59.9°F (15.5°C).Heat index
The heat index value for September is computed to be a hot 86°F (30°C). If exposure and activity persist, fatigue could ensue, possibly leading to heat cramps.It is emphasized that the heat index's values are meant for shaded zones with mild winds. Direct sunlight might lead to a heat index increase by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', marries air temperature and humidity to produce a value illustrating perceived warmth. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. When exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. 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.
Humidity
The average relative humidity in September in Rockville is 75%.Rainfall
The month with the least rainfall in Rockville is September, when the rain falls for 11.5 days and typically collects 1.93" (49mm) of precipitation.Snowfall
In Rockville, Tennessee, snow does not fall in May through September.Daylight
In Rockville, the average length of the day in September is 12h and 23min.On the first day of September in Rockville, sunrise is at 7:10 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 7:22 pm EDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
In Rockville, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The maximum daily UV index, 5 in September, converts into the following recommendations:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. 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
What are the temperatures in Rockville in September?
What is the average humidity in September in Rockville?
What is the driest month in Rockville?
How many days does it rain in September in Rockville?
When it does not snow in Rockville?
Does it snow in Rockville in September?
What is the average length of the day in September in Rockville?
What time are sunrise and sunset in September in Rockville?
How long on average sun shines in September in Rockville?
What is the UV index intensity in September in Rockville?
Average temperature in September
Rockville, TN
- Average high temperature in September: 81.1°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (45.7°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (30.6°F).
Average pressure in September
Rockville, TN
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Rockville, TN
- Average wind speed in September: 4.2mph
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 (4mph).
Average humidity in September
Rockville, TN
- Average humidity in September: 75%
The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is August (74%).
Average rainfall in September
Rockville, TN
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is February (3.9").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in September
Rockville, TN
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is November (8.8 days).
Average snowfall in September
Rockville, TN
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.1").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Rockville, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rockville, TN
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 6min).
Average sunshine days in September
Rockville, TN
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is October (19.6 days).
The month with the least sunshine days is July (11.6 days).
Average UV index in September
Rockville, TN
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Rockville, TN
- Average cloud cover in September: 29
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in September
Rockville, TN
- 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).
Rockville, Tennessee, USA
Weather forecast for your location
2. Allow the app to use your location