This report describes the typical weather at the San Jose International Airport (San Jose, California, United States) weather station over the course of an average March. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
San Jose, California has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by grasslands (44%), forests (30%), built-up areas (14%), shrublands (8%), and oceans and seas (3%).
The month of March is characterized by gradually rising daily high temperatures, with daily highs around 65°F throughout the month, exceeding 75°F or dropping below 56°F only one day in ten.
Over the course of March, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 1:12 hours, implying an average day-over-day increase of 2.3 minutes.
The shortest day of the month is March 1 with 11:24 hours of daylight; the longest day is March 31 with 12:36 hours of daylight.
The earliest sunrise is at 6:25am on March 10; the latest sunset is at 7:30pm on March 31; the latest sunrise is at 7:24am on March 11; the earliest sunset is at 6:02pm on March 1.
Daylight savings time (DST) starts at 3:00am on March 11, 2012, shifting sunrise and sunset to an hour later.
The median cloud cover ranges from 64% (partly cloudy) to 75% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 11% from the start to the end of the month.
On March 31, the clearest day of the month, the sky is clear, mostly clear, or partly cloudy 48% of the time, and overcast or mostly cloudy 44% of the time.
On March 1, the cloudiest day of the month, the sky is overcast, mostly cloudy, or partly cloudy 66% of the time, and clear or mostly clear 25% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around March 1, occurring in 33% of days. Precipitation is least likely around March 31, occurring in 26% of days.
Throughout March, the most common forms of precipitation are light rain and moderate rain.
Light rain is the most severe precipitation observed during 47% of those days with precipitation. It is most likely around March 2, when it is observed during 15% of all days.
Moderate rain is the most severe precipitation observed during 40% of those days with precipitation. It is most likely around March 1, when it is observed during 14% of all days.
Either snow is exceptionally unlikely to fall at this location in March or this station does not reliably report precipitation types.
The relative humidity typically ranges from 44% (comfortable) to 95% (very humid) over the course of a typical March, rarely dropping below 26% (dry) and reaching as high as 100% (very humid).
The air is driest around March 31, at which time the relative humidity drops below 52% (mildly humid) three days out of four; it is most humid around March 3, rising above 90% (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 March, the dew point typically varies from 39°F (dry) to 50°F (dry) and is rarely below 31°F (dry) or above 56°F (comfortable).
Over the course of March typical wind speeds vary from 0 mph to 16 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around March 31, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around March 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).