For all of the Philippines, September through March is the "rainy season" while April through August is "summer". But the weather in Sogod Bay, Southern Leyte is quite different from the rest of the Central Philippines. Unfortunately, it gets lumped into the same weather reporting as other great dive locations in central Philippines, such as Moalboal and Malapascua in Cebu, Panglao in Bohol and Dauin and Sipalay in Negros.
Sogod Bay is surrounded by high mountains and is largely protected from strong winds and regional storms; so diving conditions are good - ALL YEAR ROUND! The bay is situated just outside the so-called "typhoon belt", thereby missing the worst of the periodic cyclone activity which does affect the Eastern portions of Mindanao, Samar, and Luzon Islands.
From April through August the weather over Sogod Bay is mostly sunny, the seas are warm at 28-29 C and relatively calm, with underwater visibility of 20-30+ meters. These are excellent conditions for scuba diving, adventure tours and sight-seeing around the Sogod Bay area.
During September through March ocean currents and the prevailing North-Easterly winds, locally known as Habagat, create perfect conditions for phytoplankton to thrive in Sogod Bay. Visibility is reduced to a still respectable 15-20+ meters. The big news is that the phytoplankton draws Whale-sharks, Pilot Whales, Dolphins and large Pellagic fish into the bay.