This report describes the typical weather at the Comodoro Arturo Merino Benítez International Airport (Santiago, Chile) 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.
Santiago has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by grasslands (44%), shrublands (25%), croplands (22%), and built-up areas (6%).
Over the course of a year, the temperature typically varies from 37°F to 85°F and is rarely below 29°F or above 90°F.
The warm season lasts from November 25 to March 22 with an average daily high temperature above 80°F. The hottest day of the year is January 18, with an average high of 85°F and low of 55°F.
The cold season lasts from May 20 to September 3 with an average daily high temperature below 63°F. The coldest day of the year is July 20, with an average low of 37°F and high of 58°F.
The length of the day varies significantly over the course of the year. The shortest day is June 20 with 9:56 hours of daylight; the longest day is December 21 with 14:22 hours of daylight.
The earliest sunrise is at 6:04am on October 13 and the latest sunset is at 8:57pm on January 4. The latest sunrise is at 7:48am on June 27 and the earliest sunset is at 5:42pm on June 7.
Daylight saving time (DST) is observed in this location during 2012, starting in the spring on September 2 and ending in the fall on April 28.
The median cloud cover ranges from 2% (clear) to 72% (partly cloudy). The sky is cloudiest on June 14 and clearest on January 27. The clearer part of the year begins around October 26. The cloudier part of the year begins around April 25.
On January 27, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 71% of the time, and overcast or mostly cloudy 5% of the time.
On June 14, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 55% of the time, and clear or mostly clear 28% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around July 8, occurring in 29% of days. Precipitation is least likely around January 10, occurring in 3% of days.
Over the entire year, the most common forms of precipitation are moderate rain, light rain, and drizzle.
Moderate rain is the most severe precipitation observed during 40% of those days with precipitation. It is most likely around July 14, when it is observed during 14% of all days.
Light rain is the most severe precipitation observed during 24% of those days with precipitation. It is most likely around June 21, when it is observed during 8% of all days.
Drizzle is the most severe precipitation observed during 22% of those days with precipitation. It is most likely around August 31, when it is observed during 6% of all days.
During the warm season, which lasts from November 25 to March 22, there is a 4% 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 drizzle (33% of days with precipitation have at worst drizzle), moderate rain (26%), light rain (19%), and thunderstorms (14%).
During the cold season, which lasts from May 20 to September 3, there is a 26% 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 (45% of days with precipitation have at worst moderate rain), light rain (26%), drizzle (16%), and heavy rain (7%).
Either snow is exceptionally unlikely to fall at any time during the year at this location or this station does not reliably report precipitation types.
The relative humidity typically ranges from 31% (comfortable) to 98% (very humid) over the course of the year, rarely dropping below 21% (dry) and reaching as high as 100% (very humid).
The air is driest around January 7, at which time the relative humidity drops below 36% (comfortable) three days out of four; it is most humid around June 25, 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 35°F (dry) to 55°F (very comfortable) and is rarely below 27°F (dry) or above 60°F (comfortable).
There are two periods in the year that are most comfortable: The first is between January 1 and April 24 and the second is between October 9 and December 31. The air feels neither too dry nor too muggy during these periods.
Over the course of the year typical wind speeds vary from 0 mph to 18 mph (calm to fresh breeze), rarely exceeding 22 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around January 2, at which time the average daily maximum wind speed is 18 mph (fresh breeze).
The lowest average wind speed of 3 mph (light air) occurs around May 29, at which time the average daily maximum wind speed is 8 mph (gentle breeze).