This report describes the typical weather at the Southampton Airport (Southampton, United Kingdom) 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.
Southampton has a mild humid temperate climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (60%), oceans and seas (22%), grasslands (11%), and built-up areas (7%).
Over the course of a year, the temperature typically varies from 37Â°F to 71Â°F and is rarely below 28Â°F or above 79Â°F.
The warm season lasts from June 15 to September 11 with an average daily high temperature above 66Â°F. The hottest day of the year is August 2, with an average high of 71Â°F and low of 57Â°F.
The cold season lasts from November 18 to March 18 with an average daily high temperature below 51Â°F. The coldest day of the year is February 10, with an average low of 37Â°F and high of 46Â°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 7:55 hours of daylight; the longest day is June 20 with 16:30 hours of daylight.
The earliest sunrise is at 4:51am on June 13 and the latest sunset is at 9:24pm on June 28. The latest sunrise is at 8:09am on December 29 and the earliest sunset is at 3:59pm on December 13.
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 58% (partly cloudy) to 89% (mostly cloudy). The sky is cloudiest on January 10 and clearest on August 14. The clearer part of the year begins around April 8. The cloudier part of the year begins around October 12.
On August 14, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 56% of the time, and overcast or mostly cloudy 32% of the time.
On January 10, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 66% of the time, and clear or mostly clear 21% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around January 14, occurring in 69% of days. Precipitation is least likely around July 11, occurring in 51% of days.
Over the entire year, the most common forms of precipitation are moderate rain and light rain.
Moderate rain is the most severe precipitation observed during 62% of those days with precipitation. It is most likely around December 8, when it is observed during 42% of all days.
Light rain is the most severe precipitation observed during 15% of those days with precipitation. It is most likely around July 30, when it is observed during 10% of all days.
During the warm season, which lasts from June 15 to September 11, there is a 53% 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 (60% of days with precipitation have at worst moderate rain), light rain (18%), thunderstorms (10%), and drizzle (8%).
During the cold season, which lasts from November 18 to March 18, there is a 66% 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 (60% of days with precipitation have at worst moderate rain), light rain (13%), drizzle (10%), and heavy rain (6%).
The likelihood of snow falling is highest around February 3, occurring in 9% of days.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 51% (mildly humid) to 95% (very humid) over the course of the year, rarely dropping below 36% (comfortable) and reaching as high as 100% (very humid).
The air is driest around April 14, at which time the relative humidity drops below 59% (mildly humid) three days out of four; it is most humid around October 4, exceeding 92% (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 31Â°F (dry) to 59Â°F (comfortable) and is rarely below 21Â°F (dry) or above 64Â°F (mildy humid).
The time of the year between May 20 and October 24 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 1 mph to 13 mph (light air to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around January 13, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around August 26, at which time the average daily maximum wind speed is 10 mph (gentle breeze).