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 arrival of September corresponds with a shift in temperature, down from a warm 84.2°F (29°C) in August to a pleasant 72.7°F (22.6°C). An average temperature of 53.2°F (11.8°C) marks the nights in September.Humidity
The average relative humidity in September is 45%.Rainfall
In Hartline, Washington, in September, during 5.5 rainfall days, 0.43" (11mm) of precipitation is typically accumulated. Throughout the year, there are 102.1 rainfall days, and 9.65" (245mm) of precipitation is accumulated.Snowfall
January through April, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow. In Hartline, during the entire year, snow falls for 33.4 days and aggregates up to 14.65" (372mm) of snow.Daylight
The average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:36 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:36 pm PDT.
Sunshine
In September, the average sunshine is 10.7h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Undertake protective steps - Preventing sun damage is advised. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How much does it rain in September?
When does it start snowing?
How many hours of daylight does Hartline have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Hartline, WA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (31.6°F).
- Average low temperature in September: 53.2°F
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).
Average pressure in September
Hartline, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Hartline, WA
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).
Average humidity in September
Hartline, WA
- Average humidity in September: 45%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (36%).
Average rainfall in September
Hartline, WA
- Average rainfall in September: 0.43"
The wettest months (with the highest rainfall) are May and December (1.18").
The driest months (with the least rainfall) are July and August (0.2").
Average rainfall days in September
Hartline, WA
- Average rainfall days in September: 5.5 days
The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.2 days).
Average snowfall in September
Hartline, WA
- Average snowfall in September: 0.08"
The month with the highest snowfall is January (4.41").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Hartline, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (10.5 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Hartline, 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: 10h and 4min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Hartline, WA
- Average sunshine days in September: 23.3 days
The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is March (14.7 days).
Average UV index in September
Hartline, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in September
Hartline, WA
- Average cloud cover in September: 18
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in September
Hartline, WA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).
Hartline, Washington, USA
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