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Average Weather in August in Sunriver Oregon, United States

In Sunriver, the month of August is characterized by falling daily high temperatures, with daily highs decreasing by 5°F, from 81°F to 76°F over the course of the month, and rarely exceeding 90°F or dropping below 64°F. The highest daily average high temperature is 81°F on August 4.

Daily low temperatures decrease by 5°F, from 50°F to 45°F, rarely falling below 37°F or exceeding 58°F.

For reference, on August 3, the hottest day of the year, temperatures in Sunriver typically range from 50°F to 81°F, while on December 23, the coldest day of the year, they range from 23°F to 37°F.

Average High and Low Temperature in August

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature in August

Average Hourly Temperature in August in Sunriver12 AM4 AM8 AM12 PM4 PM8 PM12 AM181522291122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930303131JulSepchillycoldcoolcomfortablewarm
The average hourly temperature, color coded into bands: frigid < 15°F < freezing < 32°F < chilly < 45°F < cold < 55°F < cool < 65°F < comfortable < 75°F < warm < 85°F < hot < 95°F < sweltering. The shaded overlays indicate night and civil twilight.


The month of August in Sunriver experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 17% to 24%. The lowest chance of overcast or mostly cloudy conditions is 17% on August 4.

The clearest day of the month is August 4, with clear, mostly clear, or partly cloudy conditions 83% of the time.

For reference, on January 16, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 65%, while on July 28, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 83%.

Cloud Cover in August

The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.


A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Sunriver, the chance of a wet day over the course of August is gradually increasing, starting the month at 6% and ending it at 8%.

For reference, the year's highest daily chance of a wet day is 46% on November 27, and its lowest chance is 5% on August 5.

Probability of Precipitation in August

The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).


To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during August in Sunriver is essentially constant, remaining about 0.4 inches throughout, and rarely exceeding 1.2 inches or falling below -0.0 inches.

The lowest average 31-day accumulation is 0.3 inches on August 2.

Average Monthly Rainfall in August

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.


Over the course of August in Sunriver, the length of the day is rapidly decreasing. From the start to the end of the month, the length of the day decreases by 1 hour, 20 minutes, implying an average daily decrease of 2 minutes, 40 seconds, and weekly decrease of 18 minutes, 39 seconds.

The shortest day of the month is August 31, with 13 hours, 14 minutes of daylight and the longest day is August 1, with 14 hours, 34 minutes of daylight.

Hours of Daylight and Twilight in August

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise of the month in Sunriver is 5:54 AM on August 1 and the latest sunrise is 34 minutes later at 6:28 AM on August 31.

The latest sunset is 8:28 PM on August 1 and the earliest sunset is 46 minutes earlier at 7:42 PM on August 31.

Daylight saving time is observed in Sunriver during 2017, but it neither starts nor ends during August, so the entire month is in daylight saving time.

For reference, on June 21, the longest day of the year, the Sun rises at 5:23 AM and sets 15 hours, 28 minutes later, at 8:51 PM, while on December 21, the shortest day of the year, it rises at 7:37 AM and sets 8 hours, 54 minutes later, at 4:31 PM.

Sunrise & Sunset with Twilight in August

The solar day over the course of August. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray.


We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy in Sunriver is essentially constant during August, remaining around 0% throughout.

Humidity Comfort Levels in August

The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.


This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Sunriver is essentially constant during August, remaining within 0.1 miles per hour of 2.5 miles per hour throughout.

For reference, on December 1, the windiest day of the year, the daily average wind speed is 3.9 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 2.5 miles per hour.

The lowest daily average wind speed during August is 2.5 miles per hour on August 3.

Average Wind Speed in August

The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.
The hourly average wind direction in Sunriver throughout August is predominantly from the west, with a peak proportion of 41% on August 20.

Wind Direction in August

The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Solar Energy

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy in Sunriver is decreasing during August, falling by 1.3 kWh, from 7.6 kWh to 6.3 kWh, over the course of the month.

Average Daily Incident Shortwave Solar Energy in August

The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.


For the purposes of this report, the geographical coordinates of Sunriver are 43.884 deg latitude, -121.439 deg longitude, and 4,255 ft elevation.

The topography within 2 miles of Sunriver contains only modest variations in elevation, with a maximum elevation change of 344 feet and an average elevation above sea level of 4,225 feet. Within 10 miles contains only modest variations in elevation (2,356 feet). Within 50 miles contains large variations in elevation (9,308 feet).

The area within 2 miles of Sunriver is covered by trees (55%) and shrubs (42%), within 10 miles by trees (66%) and shrubs (29%), and within 50 miles by shrubs (53%) and trees (42%).

Data Sources

This report illustrates the typical weather in Sunriver year round, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 5 weather stations near enough to contribute to our estimation of the temperature and dew point in Sunriver.

For each station, the records are corrected for the elevation difference between that station and Sunriver according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Sunriver is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Sunriver and a given station.

The stations contributing to this reconstruction are: Bend Municipal Airport (74%, 30 kilometers, northeast); Mahlon Sweet Field Airport (7%, 145 kilometers, west); McNary Field (6%, 168 kilometers, northwest); Roseburg Municipal Airport (6%, 170 kilometers, southwest); and Klamath Falls Airport (7%, 195 kilometers, south).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for aiports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.