Short answer
Probably the best all-round month: warm sea, clear views, comfortable hiking temperatures and moderate crowds.
Day high28 °C
Night low22 °C
Sea26.5 °C
Rainfall140 mm
Rainy days9
SwimmingGood
Boat tripsExcellent
HikingVery good
CrowdsQuiet
01Weather
Highs around 28 °C and pleasant evenings. Rainfall drops to less than half of the August total, and clear, blue days become common. The air feels fresher as the humidity falls.
02What to do
- Full-day or overnight boat trips in calm, clear water
- The long trek to Viet Hai village
- Climbing on drier rock
- Sunset from Cannon Fort or a boat deck
03Crowds and prices
Weekends still draw domestic visitors from Hanoi and Hai Phong, but weekdays are quiet and room rates fall back from summer levels.
?Questions people ask
Is October the best time to visit Cat Ba?
For most travellers it is one of the two best months, together with November.
Is the sea warm in October?
Yes, around 26–27 °C, comfortable for swimming.