This report describes the typical weather at the El Alto International Airport (La Paz, Bolivia) weather station over the course of an average year. It is based on the historical records from 1975 to 2012. Earlier records are either unavailable or unreliable.
La Paz has a cool temperate climate with dry winters and short cool summers. The area within 25 mi of this station is covered by shrublands (55%), grasslands (39%), and forests (5%).
Over the course of a year, the temperature typically varies from 26°F to 60°F and is rarely below 22°F or above 64°F.
The warm season lasts from October 15 to December 14 with an average daily high temperature above 59°F. The hottest day of the year is November 4, with an average high of 60°F and low of 37°F.
The cold season lasts from June 7 to July 26 with an average daily high temperature below 56°F. The coldest day of the year is July 17, with an average low of 26°F and high of 55°F.
The length of the day varies significantly over the course of the year. The shortest day is June 20 with 11:09 hours of daylight; the longest day is December 21 with 13:08 hours of daylight.
The earliest sunrise is at 5:50am on November 24 and the latest sunset is at 7:13pm on January 18. The latest sunrise is at 7:02am on July 3 and the earliest sunset is at 6:06pm on June 7.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover ranges from 19% (mostly clear) to 79% (partly cloudy). The sky is cloudiest on January 20 and clearest on July 5. The clearer part of the year begins around April 17. The cloudier part of the year begins around October 9.
On July 5, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 74% of the time, and overcast or mostly cloudy 11% of the time.
On January 20, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 74% of the time, and clear or mostly clear 18% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around January 26, occurring in 80% of days. Precipitation is least likely around July 3, occurring in 9% of days.
Over the entire year, the most common forms of precipitation are thunderstorms, moderate rain, and light rain.
Thunderstorms are the most severe precipitation observed during 72% of those days with precipitation. They are most likely around January 17, when it is observed during 60% of all days.
Moderate rain is the most severe precipitation observed during 11% of those days with precipitation. It is most likely around February 3, when it is observed during 11% of all days.
Light rain is the most severe precipitation observed during 10% of those days with precipitation. It is most likely around January 30, when it is observed during 9% of all days.
During the warm season, which lasts from October 15 to December 14, there is a 58% 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 (81% of days with precipitation have at worst thunderstorms), moderate rain (8%), and light rain (7%).
During the cold season, which lasts from June 7 to July 26, there is a 10% 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 (26% of days with precipitation have at worst thunderstorms), moderate rain (19%), moderate snow (19%), and light rain (16%).
The likelihood of snow falling is highest around September 1, occurring in 5% of days.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 25% (dry) to 99% (very humid) over the course of the year, rarely dropping below 13% (very dry) and reaching as high as 100% (very humid).
The air is driest around July 26, at which time the relative humidity drops below 29% (dry) three days out of four; it is most humid around January 14, exceeding 99% (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 12°F (dry) to 43°F (dry) and is rarely below 1°F (dry) or above 46°F (dry).
Over the course of the year typical wind speeds vary from 0 mph to 16 mph (calm to moderate breeze), rarely exceeding 23 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around November 4, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around April 7, at which time the average daily maximum wind speed is 12 mph (moderate breeze).