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 advent of September brings a subtle shift in temperature, with the average high moving from a moderately hot 79.3°F (26.3°C) in August to an agreeable 71.6°F (22°C). Against the backdrop of high daytime temperatures, an average low-temperature of 49.1°F (9.5°C) is noted during September nights.Humidity
The average relative humidity in September is 72%.Rainfall
In Heisson, Washington, during September, the rain falls for 10.5 days and regularly aggregates up to 2.01" (51mm) of precipitation. In Heisson, during the entire year, the rain falls for 177.9 days and collects up to 40.67" (1033mm) of precipitation.Snowfall
April through October are months without snowfall in Heisson.Daylight
In Heisson, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:51 pm PDT.
Sunshine
In September, the average sunshine is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: A maximum UV index of 4 in September translates into the following recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Heisson in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Heisson have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Heisson, WA
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is August (79.3°F).
The month with the lowest average high temperature is December (42.6°F).
- Average low temperature in September: 49.1°F
The month with the highest average low temperature is August (52°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure in September
Heisson, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Heisson, WA
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is January (6.1mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).
Average humidity in September
Heisson, WA
- Average humidity in September: 72%
The month with the highest relative humidity is February (86%).
The month with the lowest relative humidity is August (67%).
Average rainfall in September
Heisson, WA
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is January (6.06").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days in September
Heisson, WA
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is August (5.1 days).
Average snowfall in September
Heisson, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.76").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Heisson, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.7 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
Heisson, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The months with the least sunshine are January and February (Average sunshine: 3h and 48min).
Average sunshine days in September
Heisson, WA
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is July (24.1 days).
The month with the least sunshine days is February (8.2 days).
Average UV index in September
Heisson, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Heisson, WA
- Average cloud cover in September: 36
The month with the most cloud cover is February (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
Heisson, WA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
Heisson, Washington, USA
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