This report describes the typical weather at the Mount Pleasant Royal Air Force Base (Falkland Islands) weather station over the course of an average year. It is based on the historical records from 1999 to 2012. Earlier records are either unavailable or unreliable.
Falkland Islands has a polar tundra climate. The area within 25 mi of this station is covered by tundra (57%), oceans and seas (40%), and grasslands (2%).
Over the course of a year, the temperature typically varies from 32°F to 60°F and is rarely below 27°F or above 67°F.
The warm season lasts from December 2 to March 14 with an average daily high temperature above 56°F. The hottest day of the year is January 19, with an average high of 60°F and low of 44°F.
The cold season lasts from May 23 to September 7 with an average daily high temperature below 43°F. The coldest day of the year is July 13, with an average low of 32°F and high of 40°F.
The length of the day varies significantly over the course of the year. The shortest day is June 20 with 7:47 hours of daylight; the longest day is December 21 with 16:42 hours of daylight.
The earliest sunrise is at 4:28am on December 15 and the latest sunset is at 9:16pm on December 29. The latest sunrise is at 8:04am on June 27 and the earliest sunset is at 3:48pm on June 14.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover is 85% (mostly cloudy) and does not vary substantially over the course of the year.
On February 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 38% of the time, and overcast or mostly cloudy 56% of the time.
On July 11, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 82% of the time, and clear or mostly clear 15% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around June 14, occurring in 86% of days. Precipitation is least likely around October 15, occurring in 66% of days.
Over the entire year, the most common forms of precipitation are moderate rain, light rain, and moderate snow.
Moderate rain is the most severe precipitation observed during 38% of those days with precipitation. It is most likely around February 23, when it is observed during 39% of all days.
Light rain is the most severe precipitation observed during 26% of those days with precipitation. It is most likely around January 22, when it is observed during 27% of all days.
Moderate snow is the most severe precipitation observed during 15% of those days with precipitation. It is most likely around July 9, when it is observed during 28% of all days.
During the warm season, which lasts from December 2 to March 14, there is a 73% 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 (51% of days with precipitation have at worst moderate rain), light rain (33%), and drizzle (5%).
During the cold season, which lasts from May 23 to September 7, there is a 81% 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 (29% of days with precipitation have at worst moderate snow), moderate rain (26%), light rain (19%), and light snow (15%).
The likelihood of snow falling is highest around July 14, occurring in 41% of days. The season in which it is relatively likely for snow to fall spans from April 14 to November 16.
During peak snow season, accumulation at this location on a given day is unlikely. The chances of there being snow on the ground are highest around July 19, occurring 15% of the time. The season in which snow is relatively likely to be on the ground spans from June 2 to August 5.
The snow is typically at its deepest on July 27, with a median depth of 3.0"; the depth exceeds 4.1" only one year out of ten.
The relative humidity typically ranges from 45% (comfortable) to 98% (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 December 15, at which time the relative humidity drops below 54% (mildly humid) three days out of four; it is most humid around July 15, exceeding 98% (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 27°F (dry) to 48°F (dry) and is rarely below 21°F (dry) or above 54°F (very comfortable).
Over the course of the year typical wind speeds vary from 5 mph to 31 mph (light breeze to strong breeze), rarely exceeding 41 mph (gale).
The highest average wind speed of 19 mph (fresh breeze) occurs around October 22, at which time the average daily maximum wind speed is 31 mph (strong breeze).
The lowest average wind speed of 15 mph (moderate breeze) occurs around July 18, at which time the average daily maximum wind speed is 24 mph (fresh breeze).