This report describes the typical weather at the Eugene Airport/Mahlon Sweet Field (Eugene, Oregon, United States) weather station over the course of an average year. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Eugene, Oregon has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by forests (77%), croplands (20%), and built-up areas (3%).
Over the course of a year, the temperature typically varies from 34°F to 84°F and is rarely below 25°F or above 94°F.
The warm season lasts from June 28 to September 17 with an average daily high temperature above 76°F. The hottest day of the year is July 30, with an average high of 84°F and low of 54°F.
The cold season lasts from November 13 to February 27 with an average daily high temperature below 52°F. The coldest day of the year is December 27, with an average low of 34°F and high of 45°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:52 hours of daylight; the longest day is June 20 with 15:31 hours of daylight.
The earliest sunrise is at 5:28am on June 17 and the latest sunset is at 9:01pm on June 23. The latest sunrise is at 7:53am on November 3 and the earliest sunset is at 4:34pm on December 8.
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 16% (mostly clear) to 100% (overcast). The sky is cloudiest on December 18 and clearest on August 9. The clearer part of the year begins around June 19. The cloudier part of the year begins around October 5.
On August 9, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 72% of the time, and overcast or mostly cloudy 26% of the time.
On December 18, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 85% of the time, and clear or mostly clear 14% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around December 15, occurring in 70% of days. Precipitation is least likely around August 9, occurring in 17% 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 44% of those days with precipitation. It is most likely around March 31, when it is observed during 31% of all days.
Moderate rain is the most severe precipitation observed during 40% of those days with precipitation. It is most likely around December 12, when it is observed during 30% of all days.
During the warm season, which lasts from June 28 to September 17, there is a 20% 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 (52% of days with precipitation have at worst light rain), moderate rain (28%), thunderstorms (9%), and drizzle (7%).
During the cold season, which lasts from November 13 to February 27, there is a 67% 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 moderate rain (43% of days with precipitation have at worst moderate rain), light rain (39%), light snow (7%), and heavy rain (6%).
The likelihood of snow falling is highest around January 4, occurring in 8% of days.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 34% (comfortable) to 98% (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 2, at which time the relative humidity drops below 40% (comfortable) three days out of four; it is most humid around November 12, exceeding 96% (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 32°F (dry) to 57°F (comfortable) and is rarely below 22°F (dry) or above 62°F (mildy humid).
The time of the year between May 7 and October 19 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 14 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around March 22, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around October 14, at which time the average daily maximum wind speed is 12 mph (gentle breeze).