Hạ Long, Vietnam climate

Cwa Monsoon-influenced humid subtropical

Hạ Long has a mildly seasonal tropical climate (Monsoon-influenced humid subtropical, Köppen Cwa). The hottest month is June with an average daily high near 32°C, while the coldest is January averaging around 14°C at night. Precipitation totals about 1463 mm a year and is strongly seasonal — August alone averages 327 mm while February barely receives 21 mm.

☀️ Summers

Hot

Highs near 32°C in June.

❄️ Winters

Mild

Lows near 14°C in January.

🌧️ Rain

Wet

About 1463 mm of rain a year.

Wettest in August

⛅ Sky & trend

Often grey

Overcast skies dominate much of the year.

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Hours of sunshine per day

Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)

Hạ Long climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	20	21	23	27	31	32	32	32	31	29	26	22
Avg temp (°C)	17	18	20	24	27	29	29	28	28	26	23	19
Avg low (°C)	14	15	18	21	24	26	26	25	24	22	19	15
Precipitation (mm)	38	21	55	63	181	177	234	327	218	78	45	27

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	20	21	23	27	31	32
Avg temp (°C)	17	18	20	24	27	29
Avg low (°C)	14	15	18	21	24	26
Precipitation (mm)	38	21	55	63	181	177

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	32	32	31	29	26	22
Avg temp (°C)	29	28	28	26	23	19
Avg low (°C)	26	25	24	22	19	15
Precipitation (mm)	234	327	218	78	45	27

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	72	76	79	77	74	82	81	80	71	59	59	66
Relative humidity (%)	79	81	82	82	83	86	87	86	83	80	78	76
Wind speed (mph)	6.0	5.9	5.7	5.3	5.1	5.1	5.1	4.3	4.7	5.5	5.5	6.0

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	72	76	79	77	74	82
Relative humidity (%)	79	81	82	82	83	86
Wind speed (mph)	6.0	5.9	5.7	5.3	5.1	5.1

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	81	80	71	59	59	66
Relative humidity (%)	87	86	83	80	78	76
Wind speed (mph)	5.1	4.3	4.7	5.5	5.5	6.0

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 30 years of daily observations at Phu Lien, a weather station, about 49 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →