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
Transition from August to September is accompanied by a temperature drop, with average high-temperatures decreasing from a hot 86.5°F (30.3°C) to a moderately hot 74.8°F (23.8°C). Gromore's average low-temperature during September nights is observed to be a cool 53.4°F (11.9°C).Humidity
In Gromore, the average relative humidity in September is 48%.Rainfall
In Gromore, Washington, in September, it is raining for 3.9 days, with typically 0.24" (6mm) of accumulated precipitation. In Gromore, during the entire year, the rain falls for 82.2 days and collects up to 5.43" (138mm) of precipitation.Snowfall
Months with snowfall are January through March, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Gromore, during the entire year, snow falls for 18.5 days and aggregates up to 7.8" (198mm) of snow.Daylight
The average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:41 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:43 pm PDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
In Gromore, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: A typical high UV index of 4 in September suggests the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Around midday, solar radiation is most harmful; hence, exposure should be limited. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Gromore have in September?
How high is the UV index in September?
Average temperature in September
Gromore, WA
- Average high temperature in September: 74.8°F
The warmest month (with the highest average high temperature) is August (86.5°F).
The month with the lowest average high temperature is December (36.9°F).
- Average low temperature in September: 53.4°F
The month with the highest average low temperature is August (60.3°F).
The coldest month (with the lowest average low temperature) is December (25.5°F).
Average pressure in September
Gromore, WA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in September
Gromore, WA
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest month (with the lowest average wind speed) is December (4.4mph).
Average humidity in September
Gromore, WA
- Average humidity in September: 48%
The month with the highest relative humidity is January (81%).
The months with the lowest relative humidity are July and August (39%).
Average rainfall in September
Gromore, WA
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is January (0.87").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Gromore, WA
- Average rainfall days in September: 3.9 days
The month with the highest number of rainy days is March (10.8 days).
The month with the least rainy days is August (2 days).
Average snowfall in September
Gromore, WA
- Average snowfall in September: 0.04"
The month with the highest snowfall is December (2.76").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Gromore, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (5.4 days).
The months with the least snowfall days are May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Gromore, 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: 11h and 1min
The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).
Average sunshine days in September
Gromore, WA
- Average sunshine days in September: 23.8 days
The month with the most sunshine days is July (27.5 days).
The month with the least sunshine days is February (15.8 days).
Average UV index in September
Gromore, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Gromore, WA
- Average cloud cover in September: 14
The month with the most cloud cover is January (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in September
Gromore, 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).
Gromore, Washington, USA
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