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 is marked by a subtle drop in average high-temperatures, transitioning from a moderately hot 80.8°F (27.1°C) in August to a still warm 73.8°F (23.2°C). During September, the nighttime temperature presents a clear descent from the daily peaks, falling to an average of 50°F (10°C).Humidity
The average relative humidity in September is 73%.Rainfall
In Monmouth, during September, the rain falls for 7.8 days and regularly aggregates up to 0.43" (11mm) of precipitation. Throughout the year, there are 144.6 rainfall days, and 10.04" (255mm) of precipitation is accumulated.Snowfall
In Monmouth, snow does not fall in April through November.Daylight
The average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:36 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:54 pm PDT.
Sunshine
The average sunshine in September is 9.2h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: An average UV index of 4 in September transforms into this advice:
Adopt protective measures - Suggestions to resist sunburn are offered. To guard against the harmful effects of the Sun, minimize exposure during midday. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Monmouth in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow in Monmouth?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Monmouth have in September?
What is the UV index intensity in September?
Average temperature in September
Monmouth, OR
- Average high temperature in September: 73.8°F
The warmest month (with the highest average high temperature) is August (80.8°F).
The month with the lowest average high temperature is December (44.2°F).
- Average low temperature in September: 50°F
The month with the highest average low temperature is August (52.5°F).
The coldest month (with the lowest average low temperature) is December (34.2°F).
Average pressure in September
Monmouth, OR
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in September
Monmouth, OR
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Monmouth, OR
- Average humidity in September: 73%
The months with the highest relative humidity are February and December (88%).
The month with the lowest relative humidity is August (68%).
Average rainfall in September
Monmouth, OR
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is December (1.54").
The driest month (with the least rainfall) is July (0.12").
Average rainfall days in September
Monmouth, OR
- Average rainfall days in September: 7.8 days
The month with the highest number of rainy days is March (17.8 days).
The month with the least rainy days is August (4 days).
Average snowfall in September
Monmouth, OR
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.55").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Monmouth, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.8 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
Monmouth, OR
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are July and August (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 0min).
Average sunshine days in September
Monmouth, OR
- Average sunshine days in September: 19.1 days
The month with the most sunshine days is July (24.9 days).
The month with the least sunshine days is March (9.7 days).
Average UV index in September
Monmouth, OR
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Monmouth, OR
- Average cloud cover in September: 33
The months with the most cloud cover are February and March (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Monmouth, OR
- Average visibility in September: 5mi
The month with the highest visibility is August (6mi).
The months with the lowest visibility are January, February, March, April, November and December (4mi).
Monmouth, Oregon, USA
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