San Diego Water Temperature by Month: Average Ocean Temps & Best Time to Swim

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Why Water Temperature in San Diego Matters

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San Diego’s beaches are famous for sunshine, surf culture, and year-round fun, but if you’re expecting Hawaiian-style warm waters, you may be in for a surprise. The Pacific Ocean off San Diego is cooler than most people expect, even in the summer months.

That’s why understanding the month-by-month water temperature, along with the effects of upwellings, currents, and winds, can make your trip far more enjoyable. Whether you’re swimming, snorkeling with leopard sharks in La Jolla, or surfing Mission Beach, this guide breaks down exactly what to expect.

San Diego Water Temperature by Month

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The chart below shows average monthly ocean water temperatures at San Diego beaches (based on NOAA buoy data), along with the observed ranges — since day-to-day conditions can shift quickly.

Month	Avg Temp (°F)	Observed Range (°F)	What It Feels Like	Recommended Gear
January	58–60°F	55–62°F	Very cold	Full wetsuit (4/3mm)
February	57–59°F	54–61°F	Coldest month	Full wetsuit (4/3mm)
March	58–60°F	55–62°F	Still chilly	Full wetsuit (3/2mm or 4/3mm)
April	60–62°F	57–64°F	Cold but improving	Wetsuit (3/2mm)
May	62–64°F	59–66°F	Refreshing	Springsuit or 3/2mm wetsuit
June	64–66°F	60–69°F	Cool start to summer	Springsuit / rash guard
July	66–70°F	63–72°F	Comfortable	Swim without wetsuit (rash guard optional)
August	68–72°F	64–74°F	Warmest water	Perfect for swimming/snorkeling without wetsuit
September	68–71°F	65–73°F	Still warm	No wetsuit for casual swimming
October	66–69°F	62–71°F	Cooling down	Springsuit or rash guard
November	62–65°F	59–67°F	Noticeably cooler	Full wetsuit (3/2mm)
December	59–62°F	56–64°F	Cold	Full wetsuit (4/3mm)

Why San Diego Water Temperatures Change

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Even though averages are helpful, daily conditions can shift quickly due to:

• Upwellings: Strong winds pull warm surface water offshore, replacing it with colder deep water. This can drop temps by 5–10°F in a day.

• Wind & Currents: Onshore breezes and tidal flows affect surface temps, especially near coves and bays.

• El Niño & La Niña Years: Warm El Niño years can push temps several degrees higher, while La Niña brings cooler-than-normal water.

• Microclimates: Mission Bay and La Jolla Shores can feel warmer than open-ocean spots like Sunset Cliffs.

Pro Tip: Always check live buoy data before you head out for real-time temperatures. Also, lifeguard stands have the temperature written on boards outside, and there's always popular sites and apps like Surfline that have the water temperature.

Best Months for Swimming, Surfing & Snorkeling

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See the best time of year based on the ocean temperature in San Diego.

• Swimming Without Wetsuit: July–September (warmest water, comfortable for casual swims)

• Snorkeling with Leopard Sharks: August–September in La Jolla Cove (best visibility + warm water)

• Surfing: Year-round, but wetsuits and springsuits are recommended October–June

• Family-Friendly Conditions: September is ideal — warm water + smaller crowds after summer

Gear Recommendations by Season

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San Diego’s water temperatures mean the right gear is essential. Here’s a quick guide to what you’ll need throughout the year:

Season	Temp Range	Best Gear	Top Picks
Winter (Dec–Feb)	55–62°F	Full wetsuit (4/3mm), neoprene booties	Best Men's Cold-Water Wetsuits → | Best Women's Cold-Water Wetsuits →
Spring (Mar–May)	58–66°F	3/2mm wetsuit, rash guard for warm days	Men's Surf Wetsuits for Spring → | Women's Surf Wetsuits for Spring →
Summer (Jun–Aug)	64–74°F	Rash guard, snorkel set, waterproof GoPro	Snorkel Gear for La Jolla → | Women's 1mm Front Zip Jacket →
Fall (Sep–Nov)	59–71°F	Springsuit or light wetsuit	Men's Lightweight Springsuit →

Best Gear:

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• Wetsuits → Shop the best wetsuits for San Diego surfing & swimming

• Snorkel Sets → Top-rated snorkel gear for La Jolla Cove

• Rash Guards → Lightweight rash guards for summer days

• Waterproof Camera → Capture your underwater adventures

Which Beaches Feel Warmest?

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Not all San Diego beaches feel the same — currents, depth, and geography make a difference:

• La Jolla Shores & Mission Bay: Generally warmer and calmer (best for kids, beginners, snorkeling).

• Coronado Beach: Slightly warmer, with gentler waves.

• Sunset Cliffs: Open-ocean exposure = cooler water + stronger surf.

For the warmest beaches in San Diego, keep in mind that the temperatures along the coast still won't vary too much, but If you're sensitive to cold, a degree or two might make a difference.

FAQ: San Diego Water Temperatures

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Is San Diego water warm enough to swim year-round?

Yes, but most months (Oct–May/June) require a wetsuit. July–September are warm enough for casual swimming without one.

Is the Pacific Ocean in San Diego colder than Florida?

Yes — San Diego averages 60–70°F, while Florida often ranges 75–85°F.

Why does San Diego water feel so cold even in summer?

Cold currents from Alaska and frequent upwellings keep the water cooler than tropical destinations.

What’s the warmest month for San Diego ocean water?

August is typically the warmest month, with averages near 70–72°F.

Where can I find live water temperature updates?

Check NOAA buoy data for real-time ocean temps.

Final Thoughts: Plan Smart, Swim Happy

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San Diego’s beaches offer year-round ocean adventures, but knowing the monthly water temperature helps you plan the perfect trip. Bring the right gear, check live data before you swim, and you’ll maximize comfort whether you’re surfing in January or snorkeling in September.

Ready to dive in? Don’t forget to pack the right wetsuit, snorkel set, or rash guard so you can enjoy the Pacific at its best.

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