Average Weather in Three Rivers Oregon, United States
In Three Rivers, the summers are short, warm, dry, and mostly clear and the winters are long, chilly, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 23°F to 81°F and is rarely below 10°F or above 90°F.
The warm season lasts for 2.7 months, from June 22 to September 13, with an average daily high temperature above 72°F. The hottest day of the year is August 4, with an average high of 81°F and low of 50°F.
The cold season lasts for 3.7 months, from November 12 to March 4, with an average daily high temperature below 46°F. The coldest day of the year is December 23, with an average low of 23°F and high of 37°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, 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 Three Rivers, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Three Rivers begins around June 14 and lasts for 3.8 months, ending around October 7. On July 28, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 83% of the time, and overcast or mostly cloudy 17% of the time.
The cloudier part of the year begins around October 7 and lasts for 8.2 months, ending around June 14. On January 16, the cloudiest day of the year, the sky is overcast or mostly cloudy 66% of the time, and clear, mostly clear, or partly cloudy 34% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Three Rivers varies significantly throughout the year.
The wetter season lasts 6.1 months, from October 22 to April 25, with a greater than 26% chance of a given day being a wet day. The chance of a wet day peaks at 45% on November 27.
The drier season lasts 5.9 months, from April 25 to October 22. The smallest chance of a wet day is 5% on August 5.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 32% on November 10.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Three Rivers experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 10 months, from September 4 to July 4, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around November 23, with an average total accumulation of 3.5 inches.
The rainless period of the year lasts for 2.0 months, from July 4 to September 4. The least rain falls around August 3, with an average total accumulation of 0.3 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Three Rivers experiences significant seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 5.7 months, from October 22 to April 13, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around December 20, with an average total liquid-equivalent accumulation of 1.2 inches.
The snowless period of the year lasts for 6.3 months, from April 13 to October 22. The least snow falls around August 2, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Three Rivers varies significantly over the course of the year. In 2017, the shortest day is December 21, with 8 hours, 54 minutes of daylight; the longest day is June 21, with 15 hours, 28 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:23 AM on June 15, and the latest sunrise is 2 hours, 23 minutes later at 7:46 AM on November 4. The earliest sunset is at 4:28 PM on December 9, and the latest sunset is 4 hours, 24 minutes later at 8:52 PM on June 26.
Daylight saving time (DST) is observed in Three Rivers during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
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 perceived humidity level in Three Rivers, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
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 Three Rivers experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 6.8 months, from October 22 to May 15, with average wind speeds of more than 3.1 miles per hour. The windiest day of the year is December 1, with an average hourly wind speed of 3.7 miles per hour.
The calmer time of year lasts for 5.2 months, from May 15 to October 22. The calmest day of the year is August 3, with an average hourly wind speed of 2.4 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Three Rivers varies throughout the year.
The wind is most often from the west for 7.2 months, from March 12 to October 18, with a peak percentage of 52% on June 4. The wind is most often from the south for 4.8 months, from October 18 to March 12, with a peak percentage of 57% on January 1.
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 experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.3 months, from May 15 to August 25, with an average daily incident shortwave energy per square meter above 6.7 kWh. The brightest day of the year is July 14, with an average of 8.0 kWh.
The darker period of the year lasts for 3.6 months, from October 28 to February 17, with an average daily incident shortwave energy per square meter below 2.8 kWh. The darkest day of the year is December 15, with an average of 1.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Three Rivers are 43.820 deg latitude, -121.469 deg longitude, and 4,196 ft elevation.
The topography within 2 miles of Three Rivers contains only modest variations in elevation, with a maximum elevation change of 121 feet and an average elevation above sea level of 4,185 feet. Within 10 miles contains only modest variations in elevation (2,943 feet). Within 50 miles contains large variations in elevation (9,275 feet).
The area within 2 miles of Three Rivers is covered by shrubs (50%) and trees (50%), within 10 miles by trees (65%) and shrubs (31%), and within 50 miles by shrubs (52%) and trees (43%).
This report illustrates the typical weather in Three Rivers, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Three Rivers.
For each station, the records are corrected for the elevation difference between that station and Three Rivers 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 Three Rivers is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Three Rivers and a given station.
The stations contributing to this reconstruction are: Bend Municipal Airport (75%, 37 kilometers, northeast); Mahlon Sweet Field Airport (9%, 144 kilometers, west); Roseburg Municipal Airport (8%, 165 kilometers, west); and Klamath Falls Airport (8%, 187 kilometers, south).
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.