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 signifies a gentle decline in Grand Mound's average high-temperature, easing from a moderately hot 77.4°F (25.2°C) in August to an agreeable 70.2°F (21.2°C). The nighttime temperature during September exhibits a clear drop from daytime highs, settling at a chilly 47.3°F (8.5°C).Humidity
In September, the average relative humidity is 79%.Rainfall
In Grand Mound, during September, the rain falls for 10.6 days and regularly aggregates up to 1.14" (29mm) of precipitation. Throughout the year, in Grand Mound, there are 168 rainfall days, and 23.94" (608mm) of precipitation is accumulated.Snowfall
In Grand Mound, snow does not fall in April through October.Daylight
In September, the average length of the day in Grand Mound is 12h and 32min.On the first day of September in Grand Mound, sunrise is at 6:32 am and sunset at 7:50 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:52 pm PDT.
Sunshine
The average sunshine in September in Grand Mound is 8.3h.UV index
The average daily maximum UV index in September in Grand Mound is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: A typical high UV index of 4 in September suggests the following recommendations:
Be vigilant - Preventing sunburn is recommended. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Frequently asked questions
What are the temperatures in Grand Mound in September?
What is the average humidity in September in Grand Mound?
How much does it rain in Grand Mound in September?
When it does not snow in Grand Mound?
What is the average length of the day in September in Grand Mound?
What time are sunrise and sunset in September in Grand Mound?
How many hours of sunshine does Grand Mound have in September?
How high is the UV index in September in Grand Mound?
Average temperature in September
Grand Mound, WA
- Average high temperature in September: 70.2°F
The warmest month (with the highest average high temperature) is August (77.4°F).
The month with the lowest average high temperature is December (42.6°F).
- Average low temperature in September: 47.3°F
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (33.1°F).
Average pressure in September
Grand Mound, WA
- Average pressure in September: 30.02"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 (30.02"Hg).
Average wind speed in September
Grand Mound, WA
- Average wind speed in September: 3.6mph
The windiest months (with the highest average wind speed) are January, March and November (4.5mph).
The calmest month (with the lowest average wind speed) is September (3.6mph).
Average humidity in September
Grand Mound, WA
- Average humidity in September: 79%
The month with the highest relative humidity is November (90%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Grand Mound, WA
- Average rainfall in September: 1.14"
The wettest month (with the highest rainfall) is January (3.86").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days in September
Grand Mound, WA
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (5.6 days).
Average snowfall in September
Grand Mound, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.54").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Grand Mound, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.7 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
Grand Mound, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is December (Average sunshine: 3h and 30min).
Average sunshine days in September
Grand Mound, WA
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is August (20.9 days).
The months with the least sunshine days are February and March (9.3 days).
Average UV index in September
Grand Mound, 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
Grand Mound, WA
- Average cloud cover in September: 47
The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 38).
Average visibility in September
Grand Mound, WA
- Average visibility in September: 4mi
The month with the highest visibility is July (5mi).
The months with the lowest visibility are January, February, March, April, May, June, August, September, October, November and December (4mi).
Grand Mound, Washington, USA
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