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
September ushers in a minute temperature change, with average high-temperatures reducing from August's moderately hot 73.9°F (23.3°C) to a refreshing 67.6°F (19.8°C). Throughout September, Richmond Highlands witnesses a consistent average low-temperature of 51.6°F (10.9°C).Humidity
In Richmond Highlands, the average relative humidity in September is 76%.Rainfall
In September, in Richmond Highlands, the rain falls for 11.9 days. Throughout September, 1.42" (36mm) of precipitation is accumulated. Throughout the year, there are 173 rainfall days, and 25" (635mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Richmond Highlands.Daylight
The average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:49 pm. On the last day of September, in Richmond Highlands, sunrise is at 7:08 am and sunset at 6:49 pm PDT.
Sunshine
The average sunshine in September in Richmond Highlands, Washington, is 9.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Richmond Highlands in September?
What is the average humidity in September in Richmond Highlands?
How much does it rain in Richmond Highlands in September?
When it does not snow in Richmond Highlands?
What is the average length of the day in September in Richmond Highlands?
When are sunrise and sunset in September in Richmond Highlands?
How many hours of sunshine does Richmond Highlands have in September?
What is the UV index intensity in September in Richmond Highlands?
Average temperature in September
Richmond Highlands, WA
- Average high temperature in September: 67.6°F
The warmest month (with the highest average high temperature) is August (73.9°F).
The month with the lowest average high temperature is December (43.3°F).
- Average low temperature in September: 51.6°F
The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is December (35.8°F).
Average pressure in September
Richmond Highlands, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in September
Richmond Highlands, WA
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is November (5.9mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in September
Richmond Highlands, WA
- Average humidity in September: 76%
The months with the highest relative humidity are January, February and December (84%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Richmond Highlands, WA
- Average rainfall in September: 1.42"
The wettest month (with the highest rainfall) is December (3.5").
The driest month (with the least rainfall) is July (0.39").
Average rainfall days in September
Richmond Highlands, WA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.8 days).
Average snowfall in September
Richmond Highlands, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.58").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Richmond Highlands, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.7 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Richmond Highlands, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 3min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Richmond Highlands, WA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is August (22.5 days).
The month with the least sunshine days is November (9.2 days).
Average UV index in September
Richmond Highlands, WA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Richmond Highlands, WA
- Average cloud cover in September: 32
The months with the most cloud cover are January and December (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in September
Richmond Highlands, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Richmond Highlands, Washington, USA
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