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
With the onset of September, Rockville's climate undergoes a slight change as the average high-temperature moves from 80.1°F (26.7°C) in August to a still warm 73.4°F (23°C). Throughout September, the nighttime temperature averages to a cool 54.5°F (12.5°C).Humidity
In September, the average relative humidity in Rockville is 78%.Rainfall
The month with the least rainfall in Rockville is September, when the rain falls for 7.9 days and typically collects 0.39" (10mm) of precipitation.Snowfall
June through October are months without snowfall in Rockville.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of September, in Rockville, sunrise is at 6:46 am and sunset at 6:32 pm EDT.
Sunshine
The average sunshine in September in Rockville is 8.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.Note: An average UV index of 4 in September transforms into this advice:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. 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
What are September temperatures in Rockville?
What is the average humidity in September in Rockville?
What is the driest month in Rockville?
How much does it rain in Rockville in September?
When it does not snow in Rockville?
How many hours of daylight does Rockville have in September?
When 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, CT
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (32.4°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in September
Rockville, CT
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Rockville, CT
- Average wind speed in September: 5.8mph
The windiest months (with the highest average wind speed) are January and March (8.2mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Rockville, CT
- Average humidity in September: 78%
The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (71%).
Average rainfall in September
Rockville, CT
- Average rainfall in September: 0.39"
The wettest months (with the highest rainfall) are May, June and July (1.1").
The driest month (with the least rainfall) is September (0.39").
Average rainfall days in September
Rockville, CT
- Average rainfall days in September: 7.9 days
The month with the highest number of rainy days is June (12.1 days).
The months with the least rainy days are January and February (5.5 days).
Average snowfall in September
Rockville, CT
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Rockville, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (6.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rockville, CT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 3min
The months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Rockville, CT
- Average sunshine days in September: 19.8 days
The month with the most sunshine days is January (21.9 days).
The month with the least sunshine days is June (15.7 days).
Average UV index in September
Rockville, CT
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Rockville, CT
- Average cloud cover in September: 39
The months with the most cloud cover are February and March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Rockville, CT
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, October, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August and September (5mi).
Rockville, Connecticut, USA
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