This report describes the typical weather at the Los Angeles International Airport (Los Angeles, California, United States) weather station over the course of an average January. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Los Angeles, California has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by oceans and seas (43%), built-up areas (40%), shrublands (11%), and forests (5%).
The month of January is characterized by essentially constant daily high temperatures, with daily highs around 65°F throughout the month, exceeding 76°F or dropping below 57°F only one day in ten.
Over the course of January, the length of the day is gradually increasing. The shortest day of the month is January 2 with 9:56 hours of daylight; the longest day is January 31 with 10:31 hours of daylight.
The earliest sunrise is at 6:51am on January 31; the latest sunset is at 5:23pm on January 31; the latest sunrise is at 7:00am on January 6; the earliest sunset is at 4:55pm on January 1.
Daylight savings time is observed in 2012 but it neither starts nor ends in January, so the entire month is in standard time.
The median cloud cover ranges from 46% (partly cloudy) to 55% (partly cloudy). The trend is for the sky to be becoming cloudier with the median cloud cover increasing by 9% from the start to the end of the month.
On January 16, a representative day, the sky is clear or mostly clear 45% of the time, partly cloudy 17% of the time, and mostly cloudy or overcast 38% of the time.
The average probability that some form of precipitation will be observed in a given day is 26%, with little variation over the course of the month.
Throughout January, the most common forms of precipitation are moderate rain, light rain, and heavy rain.
Moderate rain is the most severe precipitation observed during 46% of those days with precipitation. It is most likely around January 28, when it is observed during 13% of all days.
Light rain is the most severe precipitation observed during 31% of those days with precipitation. It is most likely around January 20, when it is observed during 8% of all days.
Heavy rain is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around January 26, when it is observed during 4% of all days.
Either snow is exceptionally unlikely to fall at this location in January or this station does not reliably report precipitation types.
The relative humidity typically ranges from 42% (comfortable) to 86% (very humid) over the course of a typical January, rarely dropping below 15% (very dry) and reaching as high as 100% (very humid).
The air is driest around January 1, at which time the relative humidity drops below 60% (mildly humid) three days out of four; it is most humid around January 31, rising above 80% (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 typical January, the dew point typically varies from 33°F (dry) to 51°F (very comfortable) and is rarely below 17°F (dry) or above 57°F (comfortable).
Over the course of January typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 19 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around January 31, 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 January 4, at which time the average daily maximum wind speed is 12 mph (gentle breeze).