May in Tarakan averages a daily high of 31.4°C with nights around 24.5°C. Expect roughly 10 wet days totalling 122.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Tarakan is July–January.
Based on JUWATA, ID (3.2km), 1995–2024. 14 years of May data.