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
The shift from August to September coincides with a small decrease in the average high-temperature, down to an agreeable 72.7°F (22.6°C) from a warm 80.4°F (26.9°C). During September, the nighttime temperature averages to a moderate 56.5°F (13.6°C).Humidity
In September, the average relative humidity is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.8 days and typically collects 1.5" (38mm) of precipitation.Snowfall
In Dedham, Massachusetts, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:10 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:27 pm EDT.
Sunshine
In Dedham, the average sunshine in September is 8.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The daily high UV index of 4 during September translates into the following recommendations:
Take measures. Individuals with light skin might experience burns in under 30 minutes. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Dedham in September?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
Does it snow in Dedham in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Dedham, MA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (33.6°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (21.9°F).
Average pressure in September
Dedham, MA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Dedham, MA
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Dedham, MA
- Average humidity in September: 76%
The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (70%).
Average rainfall in September
Dedham, MA
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is December (2.95").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days in September
Dedham, MA
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is July (15.8 days).
The months with the least rainy days are January and February (7.8 days).
Average snowfall in September
Dedham, MA
- Average snowfall in September: 0"
The month with the highest snowfall is March (5.24").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Dedham, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (8.2 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
Dedham, MA
- 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 2min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Dedham, MA
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is April (13.2 days).
Average UV index in September
Dedham, MA
- 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
Dedham, MA
- Average cloud cover in September: 37
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Dedham, 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).
Dedham, Massachusetts, USA
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