San Diego Coastal Marine Forecast
Updated Mon Aug 31, 2026
Confused cross-seas linger all week; use caution afloat
Drop a pin on any spot in the world — free in the SeaLegs AI app.
Marine Forecast for San Diego Aug 31 – Sep 2, 2026
📋 Confused cross-seas linger all week; use caution afloat
Winds stay manageable at 6-12 knots NW with gusts to 17 knots, but seas run 4.8-5.5 feet at 9-second periods from the SSW crossing a WNW wind-wave all day. That confused cross-sea makes for awkward, uncomfortable motion with no comfortable heading, so caution is warranted throughout.
NW winds pick up slightly to 9-15 knots with gusts to 19 knots, and a S swell crosses a WNW wind-wave for a confused, choppy sea through much of the day. Waves improve after 7:00 AM, but the awkward mixed motion from two different directions keeps this a caution day overall.
The best day of the stretch: NW winds 9-14 knots, gusts 18 knots, and 4.1-4.5 feet seas at 7-second periods from the WSW. A brief 5-hour stretch of S swell crossing WNW wind-wave creates some confused chop, but conditions are otherwise favorable, keeping this a caution-tempered GO.
Wednesday's midday hours are the best pick, with winds around 9-14 knots NW and seas dropping to 4.1-4.5 feet at 7-second periods from the WSW as the cross-sea window shrinks to just a few hours.
Today’s Water at San Diego
Sea surface temperature and chlorophyll around San Diego, imaged fresh every morning. Water at the star is 74.7°F today, and chlorophyll of 0.25 mg/m³ reads as blue-green transition water at the spot.
Imagery: Aug 31, 2026 · rebuilt every morning
These charts show you the breaks. DeepCast reads them. A zone-by-zone AI fishing report for these exact waters — temperature edges, color changes, and structure, analyzed together — for $4.99.
Get the AI fishing reportSST and chlorophyll from the SeaLegs AI DeepCast satellite pipeline. Charts are a planning aid — always check the official marine forecast before making the run.
About San Diego's coastal waters
This forecast covers the open coastal waters off San Diego — a point about 9 nautical miles west of Point Loma, in the water most local trips actually cross: the runs out of Mission Bay and San Diego Bay toward the kelp edges, the 9-Mile Bank, and the passage south toward the Coronados. It deliberately sits clear of the bays, because it is the open water, not the harbor, that decides whether a day works.
The outlook below updates every morning from the latest marine model data, with a plain GO / CAUTION / NO-GO call for each day — the same AI rating used in the SeaLegs AI app.
Reading San Diego coastal water
San Diego's defining pattern is mixed swell. WNW Pacific groundswell is the winter staple, while summer brings long-period south swell from the Southern Hemisphere — and on many days both are running at once, crossing a locally generated wind-wave. That is why the same wave height can ride so differently here: read the period and direction next to the height on every day card, and treat a crossed sea as rougher than its height suggests.
Wind follows the classic sea-breeze clock: mornings are usually the calm half of the day, with a westerly filling in through the afternoon — so a smooth run out is not a promise about the ride home. In late spring and early summer the marine layer can hold visibility down through the morning, and in the cooler months Santa Ana events reverse the pattern entirely, sending gusty offshore wind down the slopes with little warning.
This page is a planning aid, not a substitute for the National Weather Service's coastal waters forecasts and warnings — always check those before you leave the dock.
San Diego forecast FAQ
How is the sea at San Diego today?
As of Aug 31, 2026, the SeaLegs AI verdict for San Diego is CAUTION. Winds stay manageable at 6-12 knots NW with gusts to 17 knots, but seas run 4.8-5.5 feet at 9-second periods from the SSW crossing a WNW wind-wave all day. That confused cross-sea makes for awkward, uncomfortable motion with no comfortable heading, so caution is warranted throughout.
What water does this San Diego forecast cover?
The forecast point sits about 9 nautical miles west of Point Loma, in the open coastal waters zone rather than inside San Diego Bay or Mission Bay. Conditions inshore and inside the kelp line will usually be milder than shown here, while the outer banks can be rougher.
Why do the seas off San Diego often feel confused?
Because two swell trains frequently run at once — WNW Pacific groundswell and, in summer, long-period south swell from the Southern Hemisphere — crossing the local wind-wave. A crossed sea rides rougher than its height suggests, so read the period and direction together, not the height alone.
When is the wind lightest off San Diego?
Mornings, most of the year. The westerly sea breeze typically fills in and builds through the afternoon, which is why the return leg often takes more wind than the run out. In the cooler months, watch for Santa Ana events that bring gusty offshore winds instead.
Does this forecast cover the Coronado Islands or the offshore banks?
Nearby coastal water like the 9-Mile Bank and the run toward the Coronados generally behaves like this forecast point. For the far offshore grounds, see our separate Cortez Bank page, which covers the open-ocean water about 100 miles out.
What do GO, CAUTION, and NO-GO mean?
GO means conditions are favorable for most recreational boats. CAUTION means marginal — pay close attention to swell period, crossing seas, and the afternoon wind trend. NO-GO means conditions are hazardous for small craft and the trip is best postponed.
Can I get a forecast like this for my own spot?
Yes. In the free SeaLegs AI app you can drop a pin anywhere — the 9-Mile Bank, La Jolla, or your own waypoint — and get the same AI-rated marine forecast, plus fishing reports and trip planning.
What is the water temperature at San Diego today?
As of Aug 31, 2026, the satellite-derived sea surface temperature at San Diego is about 74.7°F, with chlorophyll around 0.25 mg/m³ (blue-green transition water). The SST and chlorophyll charts on this page are rebuilt every morning from the SeaLegs AI DeepCast satellite pipeline.
More offshore forecasts
Get this forecast for your own spot
Drop a pin on any spot on planet Earth in the free SeaLegs AI app — AI marine forecasts, fishing reports, and trip planning, rated GO / CAUTION / NO-GO.
📍 Get a Marine Forecast Near You →or download directly: