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
In September, the average high-temperature marginally drops from 82.8°F (28.2°C) in August to a still warm 75.9°F (24.4°C). Gwynedd, in September, experiences an average temperature of 58.3°F (14.6°C) at night.Humidity
In Gwynedd, the average relative humidity in September is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 9.4 days and typically collects 0.59" (15mm) of precipitation.Snowfall
In Gwynedd, snow does not fall in June through October.Daylight
In Gwynedd, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:29 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm EDT.
Sunshine
In Gwynedd, the average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: The UV index of 4 during September leads to these advisories:
Exercise prevention - Warding off sunburn is urged. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Gwynedd in September?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Gwynedd have in September?
What is the UV index reading in September?
Average temperature in September
Gwynedd, PA
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in September: 58.3°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (23.5°F).
Average pressure in September
Gwynedd, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Gwynedd, PA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Gwynedd, PA
- Average humidity in September: 76%
The months with the highest relative humidity are February, October and December (79%).
The months with the lowest relative humidity are April, July and August (73%).
Average rainfall in September
Gwynedd, PA
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is July (1.3").
The driest month (with the least rainfall) is September (0.59").
Average rainfall days in September
Gwynedd, PA
- Average rainfall days in September: 9.4 days
The month with the highest number of rainy days is July (13.8 days).
The months with the least rainy days are January and February (6.3 days).
Average snowfall in September
Gwynedd, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.02").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Gwynedd, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Gwynedd, PA
- Average daylight in September: 12h and 2min
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: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Gwynedd, PA
- Average sunshine days in September: 17.9 days
The month with the most sunshine days is November (22.3 days).
The month with the least sunshine days is July (13.9 days).
Average UV index in September
Gwynedd, PA
- Average UV index in September: 4
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, March, November and December (UV index 2).
Average cloud cover in September
Gwynedd, PA
- Average cloud cover in September: 38
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Gwynedd, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
Gwynedd, Pennsylvania, USA
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