This report describes the typical weather at the Geneva Cointrin International Airport (Geneva, Switzerland) 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.
Geneva has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (72%), forests (20%), and lakes and rivers (6%).
Over the course of a year, the temperature typically varies from 30Â°F to 79Â°F and is rarely below 21Â°F or above 88Â°F.
The warm season lasts from June 6 to September 8 with an average daily high temperature above 71Â°F. The hottest day of the year is July 28, with an average high of 79Â°F and low of 58Â°F.
The cold season lasts from November 15 to March 3 with an average daily high temperature below 48Â°F. The coldest day of the year is January 11, with an average low of 30Â°F and high of 40Â°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:38 hours of daylight; the longest day is June 20 with 15:48 hours of daylight.
The earliest sunrise is at 5:43am on June 17 and the latest sunset is at 9:32pm on June 24. The latest sunrise is at 8:19am on January 2 and the earliest sunset is at 4:49pm on December 10.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 25 and ending in the fall on October 28.
The median cloud cover ranges from 46% (partly cloudy) to 91% (mostly cloudy). The sky is cloudiest on December 30 and clearest on August 9. The clearer part of the year begins around June 4. The cloudier part of the year begins around September 26.
On August 9, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 61% of the time, and overcast or mostly cloudy 29% of the time.
On December 30, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 77% 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 January 15, occurring in 56% of days. Precipitation is least likely around August 9, occurring in 42% of days.
Over the entire year, the most common forms of precipitation are moderate rain, light rain, and thunderstorms.
Moderate rain is the most severe precipitation observed during 46% of those days with precipitation. It is most likely around October 23, when it is observed during 30% of all days.
Light rain is the most severe precipitation observed during 18% of those days with precipitation. It is most likely around October 16, when it is observed during 12% of all days.
Thunderstorms are the most severe precipitation observed during 17% of those days with precipitation. They are most likely around July 25, when it is observed during 21% of all days.
During the warm season, which lasts from June 6 to September 8, there is a 46% 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 thunderstorms (42% of days with precipitation have at worst thunderstorms), moderate rain (38%), and light rain (17%).
During the cold season, which lasts from November 15 to March 3, there is a 54% 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 (41% of days with precipitation have at worst moderate rain), moderate snow (21%), light rain (16%), and light snow (10%).
The likelihood of snow falling is highest around January 25, occurring in 23% of days. The season in which it is relatively likely for snow to fall spans from November 17 to March 31.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 40% (comfortable) to 95% (very humid) over the course of the year, rarely dropping below 28% (dry) and reaching as high as 100% (very humid).
The air is driest around July 21, at which time the relative humidity drops below 46% (comfortable) three days out of four; it is most humid around October 3, exceeding 93% (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 25Â°F (dry) to 60Â°F (comfortable) and is rarely below 16Â°F (dry) or above 64Â°F (mildy humid).
The time of the year between May 15 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 14 mph (calm to moderate breeze), rarely exceeding 22 mph (fresh breeze).
The highest average wind speed of 6 mph (light breeze) occurs around April 8, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 4 mph (light breeze) occurs around October 4, at which time the average daily maximum wind speed is 9 mph (gentle breeze).