January in Cat Ba Island: strong conditions, 4th of 12
Good · 7.2/10Temperatures hover around 16°C (61°F) — the kind of month where neither heat nor cold forces the schedule.
With around 36 mm of rain, any showers tend to pass through rather than settle in; about 3 days with 6+ hours of sunshine and 10.9 hours of daylight fill the rest.
That is 7.2/10 on the same scale — 4th of 12 months, versus 7.9/10 for the best month here.
Expect peak pricing, and this is one of the busiest months here.
Pack layers you can shed by midday plus one warm layer for the evening, footwear you can get muddy.
February in Cat Ba Island: mixed conditions, plan around the weather
Trade-offs · 6.5/10Temperatures hover around 17°C (63°F) — the kind of month where neither heat nor cold forces the schedule.
Budget for roughly 64 mm of rain this month — a flexible day or two helps — with about 3 days with 6+ hours of sunshine and 11.3 hours of daylight to work around it.
That is 6.5/10 on the same scale — 5th of 12 months, versus 7.9/10 for the best month here.
Budget for mid-season pricing, and crowds are moderate.
Pack layers you can shed by midday plus one warm layer for the evening, a packable rain layer, footwear you can get muddy.
March holds up well in Cat Ba Island — 3rd best month
Good · 7.4/10March averages 21°C (69°F) — warm for the outdoors: start trails early, use shaded routes at midday, and carry more water than you think you need.
Expect 44 mm of rain — occasional showers rather than washed-out days — alongside about 7 days with 6+ hours of sunshine and 11.9 daylight hours.
It scores 7.4/10 here, 3rd of 12 months, against 7.9/10 in the destination's best month.
Figure on peak pricing, with crowds are moderate. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack light clothing, a hat and real sun protection, footwear you can get muddy.
April in Cat Ba Island — workable with trade-offs
Trade-offs · 6.3/10Trail conditions at 24°C (76°F) favour early starts and shaded routes in April; midday is for water breaks, not for exposed climbs.
Budget for roughly 73 mm of rain this month — a flexible day or two helps — with about 12 days with 6+ hours of sunshine and 12.5 hours of daylight to work around it.
That is 6.3/10 on the same scale — 6th of 12 months, versus 7.9/10 for the best month here.
Budget for mid-season pricing, and crowds are moderate.
Pack light clothing, a hat and real sun protection, a packable rain layer, footwear you can get muddy.
If your dates are flexible, November is materially better in Cat Ba Island — 1.6 points higher on the same scale.
May in Cat Ba Island — off-season conditions
Hardest · 4.2/10May averages 27°C (80°F) and humidity near 86%, so the practical pattern is early mornings, a long midday break, and evenings back outside.
211 mm of rain puts this in monsoon territory — about 19 days with 6+ hours of sunshine across the whole month, and multi-day washouts are normal.
It scores 4.2/10 here, 8th of 12 months, against 7.9/10 in the destination's best month.
Plan for low-season pricing, with crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
Flexible dates? November scores 3.7 points higher here — enough to change the trip.
June in Cat Ba Island — the hardest end of the year
Hardest · 3.4/10Days in June average 29°C (83°F) and humidity near 88% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 342 mm: only about 19 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 3.4/10 on the same scale — 10th of 12 months, versus 7.9/10 for the best month here.
Expect low-season pricing, and crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
If your dates are flexible, November is materially better in Cat Ba Island — 4.5 points higher on the same scale.
July in Cat Ba Island — the hardest end of the year
Hardest · 3.8/10Days in July average 29°C (84°F) and humidity near 86% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
This is the year's wettest stretch at 338 mm, but with about 22 days with 6+ hours of sunshine it is not a total loss; an indoor fallback covers the risk.
That is 3.8/10 on the same scale — 9th of 12 months, versus 7.9/10 for the best month here.
Budget for low-season pricing, and crowds are moderate.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
If your dates are flexible, November is materially better in Cat Ba Island — 4.1 points higher on the same scale.
August in Cat Ba Island: expect compromises
Hardest · 3.3/10August averages 28°C (83°F) and humidity near 87%, so the practical pattern is early mornings, a long midday break, and evenings back outside.
421 mm of rain puts this in monsoon territory — about 18 days with 6+ hours of sunshine across the whole month, and multi-day washouts are normal.
It scores 3.3/10 here, 11th of 12 months, against 7.9/10 in the destination's best month.
Figure on low-season pricing, with crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
Flexible dates? November scores 4.6 points higher here — enough to change the trip.
September in Cat Ba Island — off-season conditions
Hardest · 3.1/10September averages 28°C (82°F) and humidity near 86%, so the practical pattern is early mornings, a long midday break, and evenings back outside.
399 mm of rain puts this in monsoon territory — about 15 days with 6+ hours of sunshine across the whole month, and multi-day washouts are normal.
It scores 3.1/10 here, 12th of 12 months, against 7.9/10 in the destination's best month.
Figure on low-season pricing, with crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
Flexible dates? November scores 4.8 points higher here — enough to change the trip.
October in Cat Ba Island — off-season conditions
Hardest · 4.9/10Trail conditions at 24°C (76°F) favour early starts and shaded routes in October; midday is for water breaks, not for exposed climbs.
160 mm of rain signals a properly wet month, with only about 13 days with 6+ hours of sunshine to count on — build indoor options into the schedule.
That is 4.9/10 on the same scale — 7th of 12 months, versus 7.9/10 for the best month here.
Budget for low-season pricing, and crowds are light for this destination.
Pack light clothing, a hat and real sun protection, a proper rain shell rather than an umbrella, footwear you can get muddy.
If your dates are flexible, November is materially better in Cat Ba Island — 3 points higher on the same scale.
November in Cat Ba Island — the year's strongest window
Best window · 7.9/10Trail conditions at 21°C (71°F) favour early starts and shaded routes in November; midday is for water breaks, not for exposed climbs.
With around 36 mm of rain, any showers tend to pass through rather than settle in; about 10 days with 6+ hours of sunshine and 11 hours of daylight fill the rest.
On our climate-comfort scale this is the top-ranked month of the year for Cat Ba Island at 7.9/10 — the reference point every other month on this page is measured against.
Budget for peak pricing, and this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack light clothing, a hat and real sun protection, footwear you can get muddy.
December holds up well in Cat Ba Island — 2nd best month
Good · 7.6/10December averages 17°C (63°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
Rain is a non-issue at 13 mm for the month, with about 5 days with 6+ hours of sunshine and 10.7 hours of daylight to work with.
It scores 7.6/10 here, 2nd of 12 months, against 7.9/10 in the destination's best month.
Plan for peak pricing, with this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack layers you can shed by midday plus one warm layer for the evening, footwear you can get muddy.
