Lebanon has diveable water twelve months a year. That is true and it is also close to useless as planning information, because February and September are not remotely the same activity.
Here is what the water actually does.
Water temperature
Beirut's sea surface temperature ranges from roughly 18 °C at its coldest to about 29 °C at its warmest. The coldest period is typically February–March; the warmest is August, sometimes into early September.
Broad seasonal averages run approximately:
| Season | Approximate sea surface temperature |
|---|---|
| Winter | ~19 °C |
| Spring | ~19–20 °C |
| Summer | ~28 °C |
| Autumn | ~26 °C |
What to actually wear, by season, is in what wetsuit you need for Mediterranean water.
Visibility — and what actually drives it
Published visibility figures for Lebanese dive sites range from about 6 metres to 25 metres. That is not sloppy reporting. It is the actual variability, and understanding what causes it is more useful than any average.
Rain and run-off are the dominant factor. Lebanon's coast collects run-off from a steep, developed catchment. After heavy rain or a storm, coastal visibility drops sharply for several days — worst near river mouths and built-up shoreline.
Consequence: the best visibility is at the end of a long dry spell. In Lebanon that means late summer and autumn.
Location matters too. The northern coast around Batroun is consistently clearer than the water near Beirut, because it is further from the run-off and development.
Plankton blooms can reduce visibility seasonally, independent of weather.
Sea state — the thing that actually cancels dives
This is the part nobody plans for and it is the part that ruins trips.
Lebanon's coastline is exposed. Wind and swell build quickly and offshore boat dives — which is most of the wreck diving — are the first thing to be called off. Temperature almost never stops a dive here. Weather does, regularly.
In winter this is frequent. A week in January might give you three diveable days or none.
In summer it is uncommon but not impossible, and the sea often builds through the day, which is why boats go out early.
Month by month
January – March
Coldest water, around 18–19 °C. Most weather cancellations. On a clear settled day the visibility can be very good indeed, because there is little boat traffic and the water is dense and cold.
Good for: local divers who can go at short notice when the forecast is right. Bad for: visitors with fixed dates. Wear: thick exposure protection, hood, gloves.
April – May
Air temperature improves before the water does. Sea still cool. Sea state improving. Some sources rate spring highly for visibility, which is plausible when the winter rain has stopped and the summer plankton has not started.
Good for: starting a course before the summer rush. Note: dress for the water, not for the weather on land.
June – July
Water warming quickly. Sea generally settled. The season proper begins.
Good for: everything. This is a strong window. Wear: thinner suit than spring, but not a shorty at depth.
August
Warmest water, around 29 °C at the surface. Also the busiest — August is peak season on the Lebanese coast for every water activity, and this is when the sand tigers are reported at Shark Point.
Good for: warm, comfortable diving; first-timers who want the least intimidating conditions. Note: book ahead. Everything is busy.
September – October
The best diving of the year. Water is still warm — autumn averages around 26 °C — the summer crowds have gone, the sea has settled, and there has typically been a long dry spell, which means the visibility is at its annual best.
If you are planning a trip around diving, plan it here.
November – December
Water cooling, weather becoming unreliable, but diveable and quiet. Early November can still be excellent.
The one-line answers
| If you want... | Go in... |
|---|---|
| The best all-round diving | September or October |
| The warmest water | August |
| The clearest water | Late September through October, on the northern coast |
| The fewest people | November, or a settled winter day |
| To do a course efficiently | June, or September–October |
| Reliable weather for a fixed-date trip | June through October |
Planning around it
If you live here: watch the forecast and go when it is flat. That flexibility is worth more than any season.
If you are visiting: aim for late September or October, build in spare days, and tell the centre in advance what you want to dive so they can sequence around the weather.
If you are visiting family over the summer: August is warm and easy and there is nothing wrong with it. Home for the summer? Get certified while you're here covers doing a course inside a holiday.
If you want the deep wrecks specifically: the Souffleur and the Batroun wrecks need settled sea more than anything else. Late summer and autumn, and be flexible about which day.
Site-by-site depths and levels are in every dive site on the Lebanese coast.
