San Diego
California, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
San Diego, CA

The view of Coronado Island in San Diego, California, from across a water body on a sidewalk, with a row of palm trees
The view of Coronado Island in San Diego, California, from across a water body on a sidewalk, with a row of palm trees
August, the last month of the summer, in San Diego, is another warm month, with average temperature varying between 65.7°F (18.7°C) and 77.4°F (25.2°C).

Temperature

August is the warmest month, with an average high-temperature of 77.4°F (25.2°C) and an average low-temperature of 65.7°F (18.7°C).

Humidity

In San Diego, the average relative humidity in August is 70%.

Rainfall

In San Diego, during August, the rain falls for 3.8 days and regularly aggregates up to 0.39" (10mm) of precipitation. Throughout the year, there are 61.8 rainfall days, and 8.7" (221mm) of precipitation is accumulated.

Ocean temperature

August is the month with the warmest seawater in San Diego, with an average ocean temperature of 68°F (20°C).
Note: Swimming in 68°F (20°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

Daylight

In August, the average length of the day is 13.3h.

Sunshine

July and August, with an average of 11.9h of sunshine, are months with the most sunshine.

UV index

Months with the highest UV index in San Diego, California, are July through September, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health hazard from unprotected exposure to the Sun's UV rays for average individuals.
Note: The daily maximum UV index of 6 in August interpret into the following advice:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the warmest month in San Diego?

The warmest month in San Diego is August, with an average high-temperature of 77.4°F (25.2°C) and an average low-temperature of 65.7°F (18.7°C).

What is the temperature in August in San Diego?

In San Diego, California, in August, the average high-temperature is 77.4°F (25.2°C), and the average low-temperature is 65.7°F (18.7°C).

What is the average humidity in August in San Diego?

The average relative humidity in August is 70%.

How many days does it rain in August in San Diego?

In August, the rain falls for 3.8 days. Throughout August, 0.39" (10mm) of precipitation is accumulated.

What month is the ocean warmest in San Diego?

With an average ocean temperature of 68°F (20°C), August is the month with the warmest seawater in San Diego, California.

How cold is the water in August in San Diego?

In August, the average ocean temperature is 68°F (20°C). For most, swimming in 68°F (20°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

What is the average length of the day in August in San Diego?

In August, the average length of the day is 13.3h.

What are the months with the most sunshine in San Diego?

July and August, with an average of 11.9h of sunshine, are months with the most sunshine in San Diego, California.

How long on average sun shines in August in San Diego?

The average sunshine in August is 11.9h.

When is the highest UV index in San Diego?

Months with the highest UV index in San Diego, California, are July through September, with an average maximum UV index of 6.

How high is the UV index in August in San Diego?

In August, the average daily maximum UV index in San Diego, California, is 6. A UV Index reading of 6 to 7 represents a high health threat from unprotected exposure to the UV radiation.
Average temperature in August - San Diego, CA
  • Average high temperature in August: 77.4°F

The warmest month (with the highest average high temperature) is August (77.4°F).
The month with the lowest average high temperature is February (63.1°F).

  • Average low temperature in August: 65.7°F

The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (51.8°F).

Average humidity in August - San Diego, CA
  • Average humidity in August: 70%

The month with the highest relative humidity is June (73%).
The month with the lowest relative humidity is November (59%).

Average rainfall in August - San Diego, CA
  • Average rainfall in August: 0.39"

The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the lowest rainfall) is June (0.12").

Average rainfall days in August - San Diego, CA
  • Average rainfall days in August: 3.8 days

The month with the highest number of rainy days is March (7.6 days).
The month with the lowest number of rainy days is June (2.7 days).

Average sea temperature in August - San Diego, CA
  • Average sea temperature in August: 67.9°F

The best month for swimming (with the highest average sea temperature) is August (67.9°F).
The coldest month (with the lowest average sea temperature) is February (58.7°F).

Average daylight in August / Average sunshine in August - San Diego, CA
  • Average daylight in August: 13.3h

The month with the longest days is June (Average daylight: 14.3h).
The month with shortest days is December (Average daylight: 10h).

  • Average sunshine in August: 11.9h

Months with most sunshine are July and August (Average sunshine: 11.9h).
The month with least sunshine is December (Average sunshine: 6.7h).

Average UV index in August - San Diego, CA
  • Average UV index in August: 6

Months with the highest UV index are July, August and September (UV index 6).
Months with the lowest UV index are January, February, March, November and December (UV index 4).