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 sea temperature 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
An average high-temperature of a refreshing 67.3°F (19.6°C) marks September, exhibiting a close resemblance to the conditions in August. During September, Hyannis perceives a slight decrease in temperature from daytime highs, settling at an average low of 62.8°F (17.1°C).Humidity
In Hyannis, the average relative humidity in September is 79%.Rainfall
In Hyannis, during September, the rain falls for 11.3 days and regularly aggregates up to 1.93" (49mm) of precipitation. Throughout the year, there are 157.2 rainfall days, and 31.77" (807mm) of precipitation is accumulated.Snowfall
In Hyannis, snow does not fall in May through November.Ocean temperature
In Hyannis, the average seawater temperature in September is 64.2°F (17.9°C).Note: Swimming in 64.2°F (17.9°C) is not a pleasurable activity for the majority of people. Breathing becomes increasingly challenging as water temperature descends from 69.8°F (21°C) to 59°F (15°C).
Daylight
In September, the average length of the day in Hyannis is 12h and 28min.On the first day of September, sunrise is at 6:07 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:37 am and sunset at 6:24 pm EDT.
Sunshine
In Hyannis, the average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September in Hyannis is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: The maximum UV index of 4 during September leads to these instructions:
Take precautions - Protection against sunburn is recommended. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Frequently asked questions
What are September temperatures in Hyannis?
What is the average humidity in September in Hyannis?
How much does it rain in Hyannis in September?
When it does not snow in Hyannis?
What is the ocean temperature in September in Hyannis?
What is the average length of the day in September in Hyannis?
When is the sunrise / sunset in September in Hyannis?
How many hours of sunshine does Hyannis have in September?
What is the UV index intensity in September in Hyannis?
Average temperature in September
Hyannis, MA
- Average high temperature in September: 67.3°F
The warmest month (with the highest average high temperature) is August (72.5°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in September: 62.8°F
The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (30.4°F).
Average pressure in September
Hyannis, MA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Hyannis, MA
- Average wind speed in September: 12.6mph
The windiest month (with the highest average wind speed) is January (16.5mph).
The calmest month (with the lowest average wind speed) is August (10.6mph).
Average humidity in September
Hyannis, MA
- Average humidity in September: 79%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is November (74%).
Average rainfall in September
Hyannis, MA
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is October (3.7").
The driest month (with the least rainfall) is August (1.73").
Average rainfall days in September
Hyannis, MA
- Average rainfall days in September: 11.3 days
The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is February (10.3 days).
Average snowfall in September
Hyannis, MA
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.93").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in September
Hyannis, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Hyannis, MA
- Average sea temperature in September: 64.3°F
The best month for swimming (with the highest average sea temperature) is August (67.5°F).
The coldest month (with the lowest average sea temperature) is March (39°F).
Average daylight in September /
Average sunshine in September
Hyannis, MA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in September
Hyannis, MA
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is August (17.7 days).
The month with the least sunshine days is February (11.4 days).
Average UV index in September
Hyannis, MA
- Average UV index in September: 4
The months with the highest UV index are 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
Hyannis, MA
- Average cloud cover in September: 31
The months with the most cloud cover are February and December (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Hyannis, MA
- 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).
Hyannis, Massachusetts, USA
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