Is It Monsoon in Dong Hoi, Vietnam? Rainfall and Weather by Month

Is It Monsoon?
Dong Hoi, Vietnam JANUARY
20°
★★★
Shoulder season
17° to 22°
Cool & Cloudy
Part of the dry season, but with less sun than the months that follow and occasionally chilly.
🧥 Light layers☂️ Cloudy skies
21°
★★★
Peak season
18° to 23°
Dry Season Holds
Dry and mild, though still one of the cloudier months of the year.
🧥 Light jacket☔ Light rain jacket
23°
★★★
Peak season
21° to 25°
Warming Up
Dry and increasingly sunny, warming steadily toward the hotter months ahead.
☀️ Sunscreen✨ Best cave-touring weather
26°
★★★
Peak season
23° to 29°
Best of the Dry Season
The mildest, least rainy month of the dry season, ideal for exploring the caves before the heat builds.
☀️ Sunscreen✨ Best cave-touring weather
29°
★★★
Shoulder season
26° to 33°
Heat Builds
Rain stays light, but the heat climbs fast as the beach-holiday months begin.
🥵 Heat protection🏖️ Beach days
31°
★★★
Shoulder season
28° to 34°
Peak Heat
The hottest month of the year, with highs that can push past 38°C.
🥵 Heat protection🏖️ Beach days
31°
★★★
Shoulder season
27° to 34°
Scorching
Nearly as hot as June, still fairly dry, with the beach the best escape from the heat.
🥵 Heat protection🏖️ Beach days
30°
★★★
Shoulder season
27° to 33°
Rains Return
Heat remains intense, but rain starts picking up as the wet season approaches.
🥵 Heat protection☔ Light rain jacket
28°
★★★
Off-peak season
25° to 31°
Monsoon Arrives
The rainy season sets in hard, with much heavier, more frequent rain than the months before it.
☔ Heavy rain gear⚠️ Flash-flood aware
26°
★★★
Off-peak season
23° to 28°
Wettest Month
The rainiest month of the year by a wide margin, with a real risk of flooding around Phong Nha.
☔ Heavy rain gear⚠️ Flash-flood aware
24°
★★★
Off-peak season
21° to 26°
Deep Monsoon
Still very wet, with sustained rain and the northeast monsoon in full force.
☔ Heavy rain gear⚠️ Flash-flood aware
21°
★★★
Shoulder season
18° to 23°
Rains Ease
The last monsoon rains linger but are usually light, easing toward the dry season ahead.
☔ Light rain jacket🧥 Light layers
Drag through the year Jan
Jan
⭐️
Feb
⭐️
Mar
⭐️
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
This month
Rainfall
61 mm
12 rainy days this month
Sunshine
3 hrs/day
23% of daylight hours
Humidity
87%
Air feels heavy and sticky
Wind
6 km/h
Light, barely noticeable
Rainfall
41 mm
11 rainy days this month
Sunshine
2.5 hrs/day
19% of daylight hours
Humidity
83%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
46 mm
11 rainy days this month
Sunshine
3.5 hrs/day
27% of daylight hours
Humidity
82%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
61 mm
9 rainy days this month
Sunshine
5.5 hrs/day
42% of daylight hours
Humidity
78%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
114 mm
10 rainy days this month
Sunshine
7.5 hrs/day
58% of daylight hours
Humidity
72%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
79 mm
7 rainy days this month
Sunshine
7.5 hrs/day
58% of daylight hours
Humidity
69%
Comfortably humid
Wind
5 km/h
Light, barely noticeable
Rainfall
76 mm
7 rainy days this month
Sunshine
7.5 hrs/day
58% of daylight hours
Humidity
72%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
165 mm
11 rainy days this month
Sunshine
6.5 hrs/day
50% of daylight hours
Humidity
73%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
475 mm
16 rainy days this month
Sunshine
5.5 hrs/day
42% of daylight hours
Humidity
78%
Air feels heavy and sticky
Wind
5 km/h
Light, barely noticeable
Rainfall
650 mm
19 rainy days this month
Sunshine
4 hrs/day
31% of daylight hours
Humidity
81%
Air feels heavy and sticky
Wind
6 km/h
Light, barely noticeable
Rainfall
320 mm
17 rainy days this month
Sunshine
3 hrs/day
23% of daylight hours
Humidity
85%
Air feels heavy and sticky
Wind
6 km/h
Light, barely noticeable
Rainfall
124 mm
14 rainy days this month
Sunshine
2.5 hrs/day
19% of daylight hours
Humidity
85%
Air feels heavy and sticky
Wind
6 km/h
Light, barely noticeable
★★★ peak season, ★★☆ decent shoulder months, ★☆☆ true off-peak, based on rain frequency, heat, and haze.
Seasons at a glance
🌟
Peak season: Feb, Mar, Apr
Dong Hoi's driest stretch, part of the broader January-to-April dry season, with April edging out as the mildest and least rainy of the bunch. February and March stay comfortably dry too, though there isn't much sun on the year's coolest days. This is the easiest window for exploring Phong Nha's caves without rain complicating boat access.
🌤️
Shoulder season: Jan, May, Jun, Jul, Aug, Dec
This tier covers real variety. January is technically part of the recommended dry season but ranks just behind its peers here. April through July bring a hot, muggy beach-holiday stretch, rain stays fairly light, but the heat can be intense, sometimes past 38°C. December still carries the last, generally light rains of the retreating monsoon. August starts seeing rain pick up again as the wet season approaches.
☔
Off-peak season: Sep, Oct, Nov
The one truly rainy stretch of the year, when the northeast monsoon delivers the bulk of Dong Hoi's annual rainfall. October is the wettest month by a wide margin, with September and November not far behind. This is also when Phong Nha's caves and rivers are most likely to see access restricted by flooding.
Good to know
✈️
Dong Hoi Airport sits close to Phong Nha
Direct flights connect to Hanoi and Ho Chi Minh City, with occasional seasonal service from Chiang Mai. Phong Nha is about 45km from the airport, roughly an hour by road.
🕳️
Son Doong, the world's largest cave, is a serious undertaking
Visiting requires a multi-day expedition booked through a single licensed operator, costs around $3,000, and is capped at roughly 1,000 permits a year, often selling out 6 to 12 months ahead. Tours only run in the dry season, January through August.
🌊
The rainy season is short but intense
September through November brings the bulk of the year's rain, with October alone accounting for a huge share of it. Flooding around the Phong Nha caves and rivers is a real possibility in this window.
🏄
Dark Cave adds adventure to a cave-touring trip
A short boat ride from Phong Nha, this cave pairs a mud bath with zip-lining and kayaking on the Chay River, a popular half-day add-on.
Top attractions
1
Phong Nha Cave
One of the longest wet caves in the world, explored by boat along an underground river, with a vast entrance chamber and dramatic stalactites.
2
Paradise Cave
The longest dry cave in Asia, with a walkway leading past towering stalagmites lit to show off the scale of the passages.
3
Dark Cave (Hang Toi)
A muddy, adventurous counterpart to the show caves, with zip-lining over the river, a natural mud bath, and kayaking back to the boat dock.