This report describes the typical weather at the Roseburg Regional Airport (Roseburg, Oregon, United States) weather station over the course of an average year. It is based on the historical records from 1990 to 2012. Earlier records are either unavailable or unreliable.
Roseburg, Oregon has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by forests (95%) and croplands (4%).
Over the course of a year, the temperature typically varies from 37°F to 86°F and is rarely below 30°F or above 96°F.
The warm season lasts from June 26 to September 21 with an average daily high temperature above 78°F. The hottest day of the year is August 4, with an average high of 86°F and low of 58°F.
The cold season lasts from November 11 to February 29 with an average daily high temperature below 55°F. The coldest day of the year is December 25, with an average low of 37°F and high of 47°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:59 hours of daylight; the longest day is June 20 with 15:23 hours of daylight.
The earliest sunrise is at 5:32am on June 13 and the latest sunset is at 8:58pm on June 27. The latest sunrise is at 7:52am on November 3 and the earliest sunset is at 4:38pm on December 9.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 2% (clear) to 98% (overcast). The sky is cloudiest on December 19 and clearest on August 6. The clearer part of the year begins around June 1. The cloudier part of the year begins around October 13.
On August 6, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 64% of the time, and overcast or mostly cloudy 17% of the time.
On December 19, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 67% of the time, and clear or mostly clear 13% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around December 12, occurring in 60% of days. Precipitation is least likely around August 8, occurring in 10% of days.
Over the entire year, the most common forms of precipitation are light rain and moderate rain.
Light rain is the most severe precipitation observed during 62% of those days with precipitation. It is most likely around February 22, when it is observed during 38% of all days.
Moderate rain is the most severe precipitation observed during 26% of those days with precipitation. It is most likely around November 30, when it is observed during 19% of all days.
During the warm season, which lasts from June 26 to September 21, there is a 13% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (63% of days with precipitation have at worst light rain), moderate rain (19%), and thunderstorms (11%).
During the cold season, which lasts from November 11 to February 29, there is a 58% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (58% of days with precipitation have at worst light rain), moderate rain (29%), heavy rain (6%), and light snow (5%).
The likelihood of snow falling is highest around January 1, occurring in 5% of days.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 33% (comfortable) to 97% (very humid) over the course of the year, rarely dropping below 21% (dry) and reaching as high as 100% (very humid).
The air is driest around August 4, at which time the relative humidity drops below 37% (comfortable) three days out of four; it is most humid around January 1, exceeding 95% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from 34°F (dry) to 57°F (comfortable) and is rarely below 28°F (dry) or above 63°F (mildy humid).
The time of the year between May 20 and October 13 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of the year typical wind speeds vary from 0 mph to 12 mph (calm to moderate breeze), rarely exceeding 16 mph (moderate breeze).
The highest average wind speed of 5 mph (light breeze) occurs around June 25, at which time the average daily maximum wind speed is 12 mph (gentle breeze).
The lowest average wind speed of 2 mph (light air) occurs around November 5, at which time the average daily maximum wind speed is 7 mph (light breeze).