July Weather at San Francisco International Airport California, United States

Daily high temperatures are around 71°F, rarely falling below 64°F or exceeding 79°F.

Daily low temperatures are around 56°F, rarely falling below 52°F or exceeding 60°F.

For reference, on September 10, the hottest day of the year, temperatures at San Francisco International Airport typically range from 57°F to 72°F, while on December 31, the coldest day of the year, they range from 45°F to 55°F.

The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on July. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Anglesea, Victoria, Australia (7,927 miles away) is the far-away foreign place with temperatures most similar to San Francisco International Airport (view comparison).

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The month of July at San Francisco International Airport experiences gradually decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 13% to 8%.

The clearest day of the month is July 19, with clear, mostly clear, or partly cloudy conditions 92% of the time.

For reference, on January 12, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 54%, while on August 7, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 92%.

Over the course of July at San Francisco International Airport, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 38 minutes, implying an average daily decrease of 1 minute, 16 seconds, and weekly decrease of 8 minutes, 49 seconds.

The shortest day of the month is July 31, with 14 hours, 5 minutes of daylight and the longest day is July 1, with 14 hours, 43 minutes of daylight.

The earliest sunrise of the month at San Francisco International Airport is 5:52 AM on July 1 and the latest sunrise is 21 minutes later at 6:13 AM on July 31.

The latest sunset is 8:34 PM on July 1 and the earliest sunset is 17 minutes earlier at 8:18 PM on July 31.

Daylight saving time is observed at San Francisco International Airport during 2024, but it neither starts nor ends during July, so the entire month is in standard time.

For reference, on June 20, the longest day of the year, the Sun rises at 5:48 AM and sets 14 hours, 46 minutes later, at 8:34 PM, while on December 21, the shortest day of the year, it rises at 7:21 AM and sets 9 hours, 34 minutes later, at 4:54 PM.

The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

The figure below presents a compact representation of key lunar data for July 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy at San Francisco International Airport is essentially constant during July, remaining around 0% throughout.

For reference, on September 5, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed at San Francisco International Airport is gradually decreasing during July, decreasing from 9.4 miles per hour to 8.5 miles per hour over the course of the month.

For reference, on May 29, the windiest day of the year, the daily average wind speed is 10.1 miles per hour, while on October 4, the calmest day of the year, the daily average wind speed is 7.5 miles per hour.

The hourly average wind direction at San Francisco International Airport throughout July is predominantly from the west, with a peak proportion of 92% on July 31.

San Francisco International Airport is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average surface water temperature at San Francisco International Airport is gradually increasing during July, rising by 2°F, from 55°F to 57°F, over the course of the month.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Temperatures at San Francisco International Airport are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

The average accumulated growing degree days at San Francisco International Airport are increasing during July, increasing by 348°F, from 1,059°F to 1,408°F, over the course of the month.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy at San Francisco International Airport is essentially constant during July, remaining within 0.2 kWh of 8.1 kWh throughout.

For the purposes of this report, the geographical coordinates of San Francisco International Airport are 37.619 deg latitude, -122.376 deg longitude, and 13 ft elevation.

The topography within 2 miles of San Francisco International Airport contains only modest variations in elevation, with a maximum elevation change of 131 feet and an average elevation above sea level of 11 feet. Within 10 miles contains only modest variations in elevation (1,909 feet). Within 50 miles contains very significant variations in elevation (4,318 feet).

The area within 2 miles of San Francisco International Airport is covered by artificial surfaces (51%) and water (46%), within 10 miles by water (45%) and artificial surfaces (30%), and within 50 miles by water (45%) and grassland (17%).