Koh Samui vs Penang

Based on sunshine hours, rain days, comfortable temperatures, and humidity levels, Koh Samui edges ahead as the better destination in May. Koh Samui offers 11 hours of daily sunshine with only 22 rain days, while Penang sees 10 sunshine hours and 27 rain days.

Koh Samui sits in the comfortable travel range at 27°C. Penang runs hot at 30°C.

For travelers who prioritize dry weather, Koh Samui is the stronger choice in May. Koh Samui receives 1 more hour of sunshine per day, which matters for sightseeing and outdoor activities.

Koh Samui reaches an average high of 27°C (81°F) and drops to 24°C (75°F) at night during May. The daily temperature range is 3°C, meaning relatively stable temperatures from day to night.

Penang averages 30°C (86°F) for the high and 26°C (79°F) for the low, with a daily range of 4°C. The 3°C difference is noticeable but not dramatic.

Both cities are in the Northern Hemisphere, so they share the same seasonal pattern in May.

Koh Samui receives approximately 115 mm of rainfall across 22 rain days during May. Rain is frequent, so waterproof gear is essential.

Penang sees 237 mm over 27 rain days. That makes Koh Samui the drier option by 5 rain days and 122 mm of total precipitation.

Both cities share similar humidity levels at 82%.