Yona Bay Water Temperature and Wetsuit Guide

Sunny with very warm air temperatures, feeling like 25 °C once we account for any wind. Sea temperatures (24 °C) warm too. Staying warm in the water won't be a problem in board-shorts, but wear at least a rash-vest to keep the UV off.

Map of current Japan Surface Water Temperatures based on measurements from oceanographic satellites

Map of current Japan Sea Water Temperature Anomalies (compared with long term averages at this time of year)

(click thumbnails to expand)

Below is a graph of Historical Sea Surface Temperature for Yona Bay. This has been derived from analysis of two decades of oceanographic satellite measurements of nearby open water. We have calculated the average water temperature variation around the year as well as the extremes that have been observed on each date.

All of the graphs for the surf breaks presented on Surf-Forecast.com are on the same scale to enable comparison between locations around the world.

Yona Bay water temperatures peak in the range 28 to 30°C (82 to 86°F) on around the 19th of July and are at their lowest on about the 22nd of February, in the range 21 to 23°C (70 to 73°F). Year round warm water temperatures at Yona Bay climb to their warmest in the third week of July. Even then a rash vest and board shorts should be fine for surfing at any time of year. Yona Bay water temperatures are lowest in the second half of February. Surfers should use a 2mm long sleeve shorty or a 3/2mm spring wetsuit if the wind is up.

Actual sea surface water temperatures close to shore at Yona Bay can vary by several degrees compared with these open water averages. This is especially true after heavy rain, close to river mouths or after long periods of strong offshore winds. Offshore winds cause colder deep water to replace surface water that has been warmed by the sun. Air temperature, wind-chill and sunshine should also be considered before deciding on the kind of wetsuit needed to stay warm when surfing at Yona Bay. Refer to our detailed weather forecasts for this information.