This report describes the typical weather at the San Diego International Airport (San Diego, California, United States) weather station over the course of an average March 29. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
San Diego, California has a cold semi-arid steppe climate. The area within 25 mi of this station is covered by oceans and seas (46%), shrublands (39%), and built-up areas (12%).
The temperature typically varies from 56°F to 65°F and is rarely below 51°F or above 72°F.
The coolest hours of the day are from 2am to 8am with the coldest at 6am, at which time the temperature is below 58°F three days out of four.
The warmest hours of the day are from 10am to 5pm with the hottest at 1pm, at which time the temperature is above 62°F three days out of four.
The day has gained half its heat by 9am and lost it again by 8pm.
On March 29 the Sun rises at 6:39am and sets at 7:07pm.
Solar noon is at 12:53pm.
For reference, on the longest day of the year the Sun rises at 5:41am and sets at 7:59pm, while on the shortest day of the year it rises at 6:47am and sets at 4:46pm.
Astronomical twilight begins and ends 82 minutes before sunrise and after sunset at 5:16am and 8:30pm, respectively.
Nautical twilight begins and ends 54 minutes before sunrise and after sunset at 5:45am and 8:00pm, respectively.
Civil twilight begins and ends 24 minutes before sunrise and after sunset at 6:15am and 7:31pm, respectively.
Solar twilight begins and ends 32 minutes after sunrise and before sunset at 7:12am and 6:34pm, respectively.
The median cloud cover ranges from 54% (partly cloudy) to 81% (mostly cloudy).
At 3pm, the clearest time of the day, the sky is clear, mostly clear, or partly cloudy 62% of the time, and overcast or mostly cloudy 38% of the time.
At 5am, the cloudiest time of the day, the sky is overcast, mostly cloudy, or partly cloudy 68% of the time, and clear or mostly clear 32% of the time.
The sky is typically clearing in earnest by 11am.
The clouds have typically started forming in earnest by midnight.
There is a 24% chance that precipitation will be observed at some point during the day.
The average measured liquid-equivalent quantity of precipitation is 0.043". Among only those days for which there is at least some measured precipitation, the average is 0.217" and the total rarely exceeds 0.494".
When precipitation does occur it is most often in the form of slight rain (49% of days with precipitation have at worst slight rain), moderate rain (31%), drizzle (8%), and heavy rain (8%).
Precipitation is most likely around 4am and least likely around 3pm.
Either snow is exceptionally unlikely to fall at this location on March 29 or this station does not reliably report precipitation types.
The relative humidity typically ranges from 59% (mildly humid) to 76% (humid), rarely dropping below 40% (comfortable), or exceeding 90% (very humid).
The air is driest at 1pm, at which time the relative humidity is less than 68% (mildly humid) three days out of four; it is most humid at 4am, exceeding 70% (humid) three days out of four.
The dew point ranges from 47°F to 50°F with an average of 49°F.
For reference, comfortable indoor conditions should have a relative humidity between 30% and 50% with a dew point of less than 65°F.
Sustained wind speeds typically vary from 5 mph to 12 mph (light breeze to gentle breeze) over the course of the day.
The peak sustained wind speed typically occurs around 2pm and is rarely outside the range 9 mph to 15 mph (gentle breeze to moderate breeze).
The wind is most calm around 5am, rarely exceeding 9 mph (gentle breeze).
The wind is most often out of the west (22% of the time), north west (21% of the time), south (13% of the time), and south west (11% of the time). The wind is least often out of the north east (3% of the time), south east (4% of the time), and east (5% of the time).