Vietnam · 1991–2020

Best time to visit
Hạ Long.

December leads for comfortable weather in Hạ Long: typically 22.3°C by day, 15.3°C at night, with 27 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortDecember

Typical high22.3°C

Typical low15.3°C

Rain in December27 mm

Comfort

December

December · February · January

93climate match

Beach

October

October · April · November

84climate match

Outdoors

January

January · February · December

88climate match

The weakest month is August, scoring 5 against December’s 93 — 343 mm of rain falls.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

8220° / 14.3°

Feb

8620.9° / 15.7°

Mar

8122.8° / 17.9°

Apr

7027.1° / 21.4°

May

3530.5° / 24.2°

Jun

2532.4° / 26°

Jul

1532.1° / 25.9°

Aug

531.7° / 25.4°

Sep

2531° / 24.4°

Oct

6029.5° / 22.2°

Nov

8226.4° / 19°

Dec

9322.3° / 15.3°

Monthly climate evidence for Hạ Long — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 32 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	20°C	14.3°C	47 mm	5	19.6°C	10 h 59	82	Strong coverage
February	20.9°C	15.7°C	22 mm	5.8	19.1°C	11 h 26	86	Good coverage
March	22.8°C	17.9°C	58 mm	10.2	20.1°C	11 h 58	81	Strong coverage
April	27.1°C	21.4°C	66 mm	7.4	22.9°C	12 h 36	70	Strong coverage
May	30.5°C	24.2°C	188 mm	8.8	26.8°C	13 h 07	35	Strong coverage
June	32.4°C	26°C	193 mm	9.4	29.0°C	13 h 24	25	Strong coverage
July	32.1°C	25.9°C	249 mm	12.2	29.4°C	13 h 17	15	Good coverage
August	31.7°C	25.4°C	343 mm	13.7	29.6°C	12 h 51	5	Strong coverage
September	31°C	24.4°C	233 mm	11.2	29.3°C	12 h 14	25	Good coverage
October	29.5°C	22.2°C	82 mm	5.6	27.7°C	11 h 38	60	Strong coverage
November	26.4°C	19°C	49 mm	4.1	25.1°C	11 h 07	82	Good coverage
December	22.3°C	15.3°C	27 mm	3.4	21.9°C	10 h 52	93	Good coverage

Records at PHU LIEN, 1974–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	29.0°C8 Jan 2020	5.5°C22 Jan 1983	102 mm6 Jan 1994	275 mm1994 · driest 0 mm in 2014	45
February	32.0°C25 Feb 2010	5.1°C21 Feb 1996	44 mm9 Feb 2021	119 mm2022 · driest 0 mm in 1991	44
March	34.8°C5 Mar 2003	5.1°C2 Mar 2006	102 mm14 Mar 2001	228 mm2001 · driest 0 mm in 1991	44
April	35.5°C19 Apr 2009	12.0°C4 Apr 1996	119 mm17 Apr 2021	175 mm2016 · driest 0 mm in 1992	41
May	39.1°C8 May 1982	15.0°C6 May 1994	199 mm7 May 1996	461 mm2012 · driest 0 mm in 1983	44
June	44.2°C12 Jun 2022	20.5°C14 Jun 2000	228 mm9 Jun 2024	405 mm2024 · driest 0 mm in 1991	45
July	39.0°C25 Jul 1977	21.2°C26 Jul 1987	259 mm21 Jul 2018	736 mm2018 · driest 0 mm in 1986	45
August	39.0°C24 Aug 2001	16.9°C27 Aug 1982	178 mm26 Aug 2022	678 mm2006 · driest 0 mm in 1986	47
September	39.9°C7 Sep 1990	15.6°C27 Sep 1997	214 mm11 Sep 2024	422 mm2024 · driest 0 mm in 1990	48
October	34.4°C5 Oct 2023	13.3°C30 Oct 1988	208 mm29 Oct 2012	349 mm2017 · driest 0 mm in 1989	48
November	33.1°C6 Nov 2023	10.4°C28 Nov 2007	128 mm3 Nov 2005	240 mm2005 · driest 0 mm in 1986	47
December	35.4°C15 Dec 1984	0.0°C14 Dec 1975	101 mm1 Dec 2005	131 mm2005 · driest 0 mm in 1987	48

Typical days per month at PHU LIEN, 1991–2020
Month	Days 25°C+	Days 30°C+	Heavy rain (10 mm+)
January	3	0	<1
February	5	<1	<1
March	8	<1	1
April	20	5	1
May	27	19	4
June	27	24	4
July	28	24	5
August	28	23	7
September	27	21	5
October	27	16	1
November	19	4	1
December	7	0	<1

How often, not how much — every day in PHU LIEN’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	50%	16%	3%	23%	17.3–21.8°C
February	53%	21%	2%	22%	17.8–23.5°C
March	62%	31%	4%	46%	20.9–24.9°C
April	76%	24%	6%	25%	25.5–28.9°C
May	68%	29%	13%	38%	29.2–31.6°C
June	68%	31%	17%	50%	31.5–33.3°C
July	61%	38%	20%	56%	31.0–33.3°C
August	58%	43%	27%	68%	30.9–32.5°C
September	65%	37%	19%	49%	30.0–31.9°C
October	83%	18%	6%	18%	27.8–30.1°C
November	85%	13%	4%	15%	24.3–27.4°C
December	70%	10%	2%	8%	20.3–23.8°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1976Each stripe is one year’s mean temperature against the 23-year average. Warmest: 2003. Coolest: 2011.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 1580410
NOAA station: VMM00048826 · PHU LIEN
Station distance: 48.7 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 24 usable years
Daylight: Calculated from latitude 20.95°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 32 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from PHU LIEN is what differs

Haiphong→Thị Trấn Đông Triều→Hải Dương→Chí Linh→Kiến An→Thị Trấn Mạo Khê→

Or put two places side by side: Hạ Long vs Haiphong

Best time to visitHạ Long.