This report describes the typical weather at the Santa Monica Airport (Santa Monica, California, United States) weather station over the course of an average August. It is based on the historical records from 1983 to 2012. Earlier records are either unavailable or unreliable.
Santa Monica, California has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by built-up areas (39%), oceans and seas (32%), shrublands (21%), and forests (8%).
The month of August is characterized by essentially constant daily high temperatures, with daily highs around 76°F throughout the month, exceeding 83°F or dropping below 71°F only one day in ten.
Over the course of August, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 55 minutes, implying an average day-over-day decrease of 1.8 minutes.
The shortest day of the month is August 31 with 12:53 hours of daylight; the longest day is August 1 with 13:48 hours of daylight.
The earliest sunrise is at 6:05am on August 1; the latest sunset is at 7:54pm on August 1; the latest sunrise is at 6:27am on August 31; the earliest sunset is at 7:21pm on August 31.
Daylight savings time is observed in 2012 but it neither starts nor ends in August, so the entire month is in daylight time.
The median cloud cover is 26% (mostly clear) and does not vary substantially over the course of the month.
On August 16, a representative day, the sky is clear or mostly clear 49% of the time, partly cloudy 3% of the time, and mostly cloudy or overcast 22% of the time.
The average probability that some form of precipitation will be observed in a given day is 3%, with little variation over the course of the month.
Throughout August, the most common forms of precipitation are light rain, drizzle, moderate rain, and thunderstorms.
Light rain is the most severe precipitation observed during 51% of those days with precipitation. It is most likely around August 26, when it is observed during 2% of all days.
Drizzle is the most severe precipitation observed during 20% of those days with precipitation. It is most likely around August 6, when it is observed during 1% of all days.
Moderate rain is the most severe precipitation observed during 15% of those days with precipitation. It is most likely around August 31, when it is observed during 1% of all days.
Thunderstorms are the most severe precipitation observed during 10% of those days with precipitation. They are most likely around August 24, when it is observed during 0% of all days.
Either snow is exceptionally unlikely to fall at this location in August or this station does not reliably report precipitation types.
The relative humidity typically ranges from 59% (mildly humid) to 89% (very humid) over the course of a typical August, rarely dropping below 47% (comfortable) and reaching as high as 96% (very humid).
The air is driest around August 31, at which time the relative humidity drops below 66% (mildly humid) three days out of four; it is most humid around August 1, rising above 86% (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 typical August, the dew point typically varies from 58°F (comfortable) to 63°F (mildy humid) and is rarely below 54°F (very comfortable) or above 67°F (muggy).
The time of the month between August 1 and August 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of August typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 17 mph (moderate breeze).
The highest average wind speed of 7 mph (light breeze) occurs around August 1, 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 31, at which time the average daily maximum wind speed is 13 mph (moderate breeze).