This report describes the typical weather at the Vienna International Airport (Schwechat Airport) (Vienna, Austria) 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.
Vienna has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (78%), grasslands (11%), forests (5%), built-up areas (5%), and lakes and rivers (3%).
Over the course of a year, the temperature typically varies from 27°F to 79°F and is rarely below 15°F or above 88°F.
The warm season lasts from May 26 to September 9 with an average daily high temperature above 70°F. The hottest day of the year is August 8, with an average high of 79°F and low of 60°F.
The cold season lasts from November 17 to March 3 with an average daily high temperature below 45°F. The coldest day of the year is January 9, with an average low of 27°F and high of 36°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:21 hours of daylight; the longest day is June 20 with 16:05 hours of daylight.
The earliest sunrise is at 4:53am on June 18 and the latest sunset is at 8:58pm on June 23. The latest sunrise is at 7:45am on December 30 and the earliest sunset is at 3:59pm on December 12.
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 44% (partly cloudy) to 89% (mostly cloudy). The sky is cloudiest on December 12 and clearest on July 26. The clearer part of the year begins around April 11. The cloudier part of the year begins around October 8.
On July 26, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 71% of the time, and overcast or mostly cloudy 25% of the time.
On December 12, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 78% of the time, and clear or mostly clear 20% 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 67% of days. Precipitation is least likely around September 19, occurring in 45% of days.
Over the entire year, the most common forms of precipitation are moderate rain, moderate snow, light rain, and thunderstorms.
Moderate rain is the most severe precipitation observed during 49% of those days with precipitation. It is most likely around April 22, when it is observed during 34% of all days.
Moderate snow is the most severe precipitation observed during 15% of those days with precipitation. It is most likely around January 24, when it is observed during 26% of all days.
Light rain is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around October 1, when it is observed during 9% of all days.
Thunderstorms are the most severe precipitation observed during 13% of those days with precipitation. They are most likely around July 10, when it is observed during 19% of all days.
During the warm season, which lasts from May 26 to September 9, there is a 52% 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 (53% of days with precipitation have at worst moderate rain), thunderstorms (31%), and light rain (14%).
During the cold season, which lasts from November 17 to March 3, there is a 63% 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 snow (35% of days with precipitation have at worst moderate snow), moderate rain (35%), light rain (10%), and light snow (9%).
The likelihood of snow falling is highest around January 24, occurring in 35% of days. The season in which it is relatively likely for snow to fall spans from November 11 to March 31.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 44% (comfortable) to 94% (very humid) over the course of the year, rarely dropping below 30% (comfortable) and reaching as high as 100% (very humid).
The air is driest around April 24, at which time the relative humidity drops below 51% (mildly humid) three days out of four; it is most humid around November 30, exceeding 91% (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 22°F (dry) to 60°F (comfortable) and is rarely below 9°F (dry) or above 66°F (muggy).
The time of the year between May 9 and October 8 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 2 mph to 18 mph (light air to fresh breeze), rarely exceeding 29 mph (strong breeze).
The highest average wind speed of 11 mph (gentle breeze) occurs around February 5, at which time the average daily maximum wind speed is 18 mph (fresh breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around August 11, at which time the average daily maximum wind speed is 14 mph (moderate breeze).