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 transition into September subtly indicates a reduction in the average high-temperature, down to a refreshing 64.2°F (17.9°C) from August's agreeable 70.7°F (21.5°C). Throughout September, a steady low-temperature average of 47.8°F (8.8°C) is noted.Humidity
The average relative humidity in September is 79%.Rainfall
In Lyman, Washington, in September, it is raining for 13.5 days, with typically 2.76" (70mm) of accumulated precipitation. Throughout the year, there are 203.2 rainfall days, and 49.72" (1263mm) of precipitation is accumulated.Snowfall
In Lyman, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 34min.On the first day of September, sunrise is at 6:26 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:48 pm PDT.
Sunshine
In Lyman, the average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the UV index of 3 transforms into the following advice:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Lyman in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Lyman have in September?
What is the UV index reading in September?
Average temperature in September
Lyman, WA
- Average high temperature in September: 64.2°F
The warmest month (with the highest average high temperature) is July (70.9°F).
The month with the lowest average high temperature is December (40.5°F).
- Average low temperature in September: 47.8°F
The month with the highest average low temperature is August (50.5°F).
The coldest months (with the lowest average low temperature) are February and December (32.5°F).
Average pressure in September
Lyman, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Lyman, WA
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is November (5.7mph).
The calmest month (with the lowest average wind speed) is August (3.3mph).
Average humidity in September
Lyman, WA
- Average humidity in September: 79%
The months with the highest relative humidity are January, February and March (86%).
The month with the lowest relative humidity is July (75%).
Average rainfall in September
Lyman, WA
- Average rainfall in September: 2.76"
The wettest month (with the highest rainfall) is November (7.09").
The driest month (with the least rainfall) is July (0.98").
Average rainfall days in September
Lyman, WA
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is March (22.1 days).
The month with the least rainy days is August (9.4 days).
Average snowfall in September
Lyman, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.96").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Lyman, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.3 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
Lyman, WA
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 3h and 30min).
Average sunshine days in September
Lyman, WA
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is August (19.2 days).
The month with the least sunshine days is March (7.3 days).
Average UV index in September
Lyman, WA
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Lyman, WA
- Average cloud cover in September: 37
The month with the most cloud cover is December (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Lyman, WA
- Average visibility in September: 5mi
The months with the highest visibility are June, July and August (6mi).
The months with the lowest visibility are January, February, March, April, May, September, October, November and December (5mi).
Lyman, Washington, USA
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