August weather forecastSisters, OR
August
Weather in August
The peak of summer reaches a plateau in August. Sisters upholds a high-end temperature around a stable 78.4°F (25.8°C), maintaining July's warmth. Concurrently, the rainfall index inches slightly upwards as the month progresses. The sheer volume of sunshine hours stays significantly high, although a slight wane from the preceding month is noticeable. Despite maintaining a uniform wind speed, a thinning cloud cover lets sufficient sunshine seep through allowing residents to relish in the last bits of summer.Temperature
As Sisters welcomes August, the average high-temperature is noted at a still moderately hot 78.4°F (25.8°C), closely aligning with the preceding month. Sisters marks a considerable descent from the daytime apex, as the average temperature dips to a cool 50.7°F (10.4°C) at night throughout August.Humidity
July and August, with an average relative humidity of 53%, are the least humid months.Rainfall
In Sisters, during August, the rain falls for 6.1 days and regularly aggregates up to 0.51" (13mm) of precipitation. In Sisters, Oregon, during the entire year, the rain falls for 142.1 days and collects up to 22.87" (581mm) of precipitation.Snowfall
June through August are months without snowfall in Sisters.Daylight
The average length of the day in August is 13h and 58min.On the first day of August in Sisters, sunrise is at 5:54 am and sunset at 8:30 pm. On the last day of the month, sunrise is at 6:28 am and sunset at 7:43 pm PDT.
Sunshine
The average sunshine in August is 11.8h.UV index
In August, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: An average UV index of 4 in August transforms into this advice:
Undertake protective steps - Recommendations to avoid sunburn are issued. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Sisters, OR
- Average high temperature in August: 78.4°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is December (36.5°F).
- Average low temperature in August: 50.7°F
The month with the highest average low temperature is August (50.7°F).
The coldest month (with the lowest average low temperature) is December (24.8°F).
Average pressure in August
Sisters, OR
- Average pressure in August: 29.98"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.98"Hg).
Average wind speed in August
Sisters, OR
- Average wind speed in August: 4.8mph
The windiest month (with the highest average wind speed) is February (6.1mph).
The calmest months (with the lowest average wind speed) are August and September (4.8mph).
Average humidity in August
Sisters, OR
- Average humidity in August: 53%
The month with the highest relative humidity is December (84%).
The months with the lowest relative humidity are July and August (53%).
Average rainfall in August
Sisters, OR
- Average rainfall in August: 0.51"
The wettest month (with the highest rainfall) is January (3.31").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days in August
Sisters, OR
- Average rainfall days in August: 6.1 days
The month with the highest number of rainy days is March (16.9 days).
The month with the least rainy days is July (5 days).
Average snowfall in August
Sisters, OR
- Average snowfall in August: 0"
The month with the highest snowfall is February (13.74").
The months with the least snowfall are June, July and August (0").
Average snowfall days in August
Sisters, OR
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is December (14.7 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in August /
Average sunshine in August
Sisters, OR
- Average daylight in August: 14h and 0min
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 August: 11h and 48min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in August
Sisters, OR
- Average sunshine days in August: 21.8 days
The month with the most sunshine days is July (23.3 days).
The month with the least sunshine days is March (8.1 days).
Average UV index in August
Sisters, OR
- Average UV index in August: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in August
Sisters, OR
- Average cloud cover in August: 12
The months with the most cloud cover are January, February, March and December (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in August
Sisters, OR
- Average visibility in August: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
