Aliso Beach Water Temperature & Swim Forecast
Family south-Laguna beach.
Pleasant water with a light chop and a light breeze — good swimming conditions.
Model estimate · modelled, not a buoy measurement. How accurate is this?
Location
Aliso Beach on the map, with nearby beaches and live sea temperatures.
7-day forecast
Water, air, waves, wind and UV outlook for the week ahead.
Shorty 2mm
At 21.7°C a 2mm shorty keeps surfers warm; lap swimmers can usually skip the neoprene.
Recommendation tuned for Aliso Beach's current water temperature. Individual tolerance, wind chill, and session length all matter — when in doubt, size up.
Aliso Beach swimming conditions summary
- Water temperature
- 21.7°C
- Water feels
- Pleasant
- Swimmable today
- Yes — comfortable for most swimmers
- Swim conditions score
- 83/100 · Excellent
- Wetsuit needed
- Shorty 2mm
- Air temperature
- —
- Waves
- —
- Wind
- —
- UV index
- —
- Average sea temperature (September)
- 21.0 °C
- Warmest months to swim
- July, August, September
At 21.7°C a 2mm shorty keeps surfers warm; lap swimmers can usually skip the neoprene. Model estimate. Water, wave, wind and UV values are Open-Meteo marine/weather model estimates, refreshed hourly — not buoy measurements.
Frequently asked questions
Can I swim at Aliso Beach right now?
The sea at Aliso Beach is currently 21.7°C — good swimming conditions. Most swimmers will find the water comfortable when it's above 22°C; below 18°C feels fresh and a wetsuit is recommended.
What will the sea temperature be at Aliso Beach next week?
Based on long-term September averages and the latest marine model, expect the sea around Aliso Beach to sit close to 20.3°C over the next 7 days. Check the live 7-day chart above for the exact daily outlook.
When is the best month to swim at Aliso Beach?
July – August – September are typically the warmest months to swim at Aliso Beach, with sea temperatures at their seasonal peak.
Do I need a wetsuit at Aliso Beach?
With water currently at 21.7°C: above 22°C no wetsuit needed; 18–22°C a shorty is comfortable for long swims; 14–18°C a 3/2mm full suit; below 14°C a 4/3mm or thicker.
Can I swim at Aliso Beach today?
The sea is currently 21.7°C — excellent swimming conditions. Most swimmers will find it pleasant.
- • Located in Southern California, United States (Pacific Ocean).
- • Family friendly with calm, accessible water.
- • Live data refreshed hourly from Open-Meteo Marine.
Monthly sea temperature averages
Tap any month to see what to expect — based on regional climatology.
Best time to swim in Aliso Beach
The sea in Aliso Beach peaks in August, when the water averages around 22°C.
The main swimming season runs from July – October, when surface temperatures stay comfortable for extended sessions.
On average, 4 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
Shoulder months like June and November are noticeably cooler but often quieter, with fewer crowds and steadier weather.
Outside peak season the water drops toward 15°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.
The coldest month is typically January at around 15°C, when cold-water swimmers dominate the coast.
Aliso Beach sea temperature history
Long-term climatology for Aliso Beach shows an annual mean sea temperature of 18°C, ranging from 15°C in winter to 22°C at the summer peak.
The seasonal swing is roughly 7°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Aliso Beach, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Aliso Beach sea temperature: frequently asked questions
What is the warmest month to swim in Aliso Beach?
August is the warmest month in Aliso Beach, when the sea averages about 22°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Aliso Beach?
The coldest month in Aliso Beach is typically January, when the water averages around 15°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Aliso Beach without a wetsuit?
The main swimming season in Aliso Beach runs from July – October — about 4 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Aliso Beach?
Outside peak summer the water in Aliso Beach drops toward 15°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Aliso Beach?
The long-term annual mean sea temperature in Aliso Beach is about 18°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Aliso Beach?
The live reading at the top of this page shows the current sea temperature in Aliso Beach, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Year-round sea temperature
Best swim months: Jul – Aug – Sep – Oct
| Month | Sea | Comfort |
|---|---|---|
| Jan | 15°C | Bracing |
| Feb | 15°C | Bracing |
| Mar | 15°C | Bracing |
| Apr | 16°C | Bracing |
| May | 17°C | Bracing |
| Jun | 19°C | Pleasant |
| Jul | 21°C | Pleasant |
| Aug ⭐ | 22°C | Warm |
| Sep | 21°C | Pleasant |
| Oct | 20°C | Pleasant |
| Nov | 17°C | Bracing |
| Dec | 16°C | Bracing |
Nearby beaches
The closest coastline, with live water temperatures.