San Diego Weather in September: What’s It Like?

San Diego Weather in September

San Diego is famous for its world-class beaches and laid-back lifestyle. But have you ever wondered what the weather is like in San Diego in September?

Long after the summer crowds have gone and the kids are all back in school, San Diego sunshine is still around, and it’s the perfect time to enjoy a little beach vacation.  

With perfect weather and amazing beaches, whether you are visiting for the first time or have been hanging out in San Diego for years, there are plenty of things to do in San Diego for adults and kids alike. 

How Is the Weather in San Diego in September?

If you’re planning a trip and wondering if San Diego is nice in September, the answer is YES! 

San Diego weather in September, or any time for that matter, is fantastic. The warmest month in San Diego is in August, with the hottest day of the year being the 26th of the month. September sees a slight cooling trend but not by much. 

The weather in San Diego, California, in September, is a temperate 72 degrees. 

Of course, the average weather in San Diego in September doesn’t differentiate too much throughout the year, so there’s never a bad time to visit.  Still, September is one of the least crowded months, so consider that in your travel plans.

Is September a Good Time to Visit San Diego?

To get all the benefits of San Diego without the crowds, September is one of the best months to visit. To understand why, the question to be answered is, “what is the weather like in San Diego in September?”

Simply, the answer is that San Diego weather in late September or any time of the month is incredible. Daytime weather is still warm enough for the beaches and other outdoor activities, and nighttime is a comfortable 65 degrees. 

There are so many different activities to consider if you plan on visiting in September. You can check out some of the attractions at the world-famous zoo, or the museums in Balboa Park, Sea World, catch a game of the San Diego Padres baseball, and of course the beaches. And depending on where you stay and how long you will be in San Diego, you can check out our list of things to do in North County San Diego.

Is San Diego Warm in September?

Daytime temperatures in September average 72 degrees during the day and 65 degrees at night, which is one reason San Diego has earned the moniker “America’s Finest City.”

What Should I Wear in San Diego in September?

Weather in San Diego, California in September is always comfortable. In other words, San Diego weather in September is an ideal 72 degrees and drops about 6 degrees in the evening. 

Light clothing with a jacket or sweatshirt is recommended, though you can comfortably get by with shorts and a T-shirt. No need to overpack the winter coats or heavy shirts. San Diego weather is perfect for fun-in-the-sun comfortable clothing.

Can You Swim in San Diego in September?

Yes! In September, the water temperature is a mild 66 degrees. And ocean swells stemming from tropical storms in the south of Baja Mexico can sometimes bring with them even warmer water temperatures!

What Is There To Do in San Diego in September?

September is one of the best months in San Diego. The summertime crowds are gone, kids are back in school, and San Diego weather in September is perfect. There are so many activities and things to do in San Diego in the month of September. 

You can check out the San Diego Padres at Petco Park downtown or cruise out to Sea World for the day. The museums and restaurants around Balboa Park are incredible, and if it’s just you and your significant other, there are plenty of date night ideas in San Diego.

Some of our top suggestions of things to do in San Diego;

  • San Diego Zoo and Wild Animal Park
  • San Diego Padres at Petco Park
  • San Diego Area Beaches and Bays
  • Museums in Balboa Park
  • Seaport Village
  • Little Italy
  • Historic Gaslamp District
  • Sea World 
  • Coronado Island
  • La Jolla Cove
  • Torrey Pines State Park and Golf Resort
  • Legoland

Temperature in September

San Diego Weather in September doesn’t differ much from the rest of the year. Typically it’s in the low-to-mid ’70s during the day, with nighttime temperatures hovering in the mid-to-low ’60s. 

Humidity in September

June is the most humid of the months in San Diego. However, July through September can have occasionally higher humidity levels due to warm ocean currents from Mexico being pushed northward. 

In general, humidity in San Diego hovers around 68%, making the average San Diego weather in September more moderate and comfortable than most places in the United States.  

Sunshine in September

San Diego Weather in September is known for moderate temperatures with ample sunshine. However, in September, there is a phenomenon known as the Santa Ana Winds, which are dry, warm air blown from the deserts toward the ocean keeping much of the area clear of clouds. 

This moderate climate makes San Diego beach weather in September perfect for those fortunate to come to visit at that time. If you’re looking for other suggestions, you can check out the award-winning restaurants of Del Mar, La Jolla, Little Italy, or in the Historic Gaslamp District.

Wind in September

Except in rare circumstances, the average wind in San Diego for September is below 5 miles per hour, though an occasional Santa Ana may increase the wind. 

Rainfall in September

September is one of the driest months in San Diego, having an average level of precipitation at 0.21” while the rainiest months are the winter season from January through March.

Clouds in September

Due to the warm weather and offshore winds, clouds are not an abundant feature in San Diego. In fact, there are more sunny days in September than some of the peak days of summer. 

Ocean Temperature in September

The average water temperature for San Diego in the month of September is a mild 67 degrees, meaning that with warm daylight and mild water temperatures, the beaches are a great way to spend your time. On occasion, a south-swell will push warmer tropical waters northward into San Diego. 

Daylight in September

Daylight in San Diego for September begins approximately at 6:30 am with sunset around 7:15 pm for a total of 13 hours of sunlight per day. The ample daylight is perfect for sunbathing, surfing, shopping, checking out local attractions, hiking, and more. 

San Diego Weather In September Makes It The Best Time To Visit 

The average San Diego Weather in September is mild and comfortable, making it an ideal time to vacation and explore all that San Diego has to offer. 

You can still get the beach time you want without the summer crowds, check out all that makes San Diego “America’s Finest City,” and have the vacation you deserve.

About the author: David Throop is a freelance writer specializing in marketing, health, fitness, and wellness with an eye toward his clients achieving their outcome objectives. When he is not being bitten on the ankles by precocious puppies and children he likes to spend his time outdoors.