The best time to visit Northern Vietnam

The Red River delta and the karst country above it — flat, unlike the central coast, so the data behaves. Daytime highs in northern Vietnam run from about 18 °C in January to 30 °C in July, an annual range of roughly 12 °C.

Measured against a city trip, the conditions hold up November to March. January is the most consistent single month: highs near 18 °C, nights around 12 °C, and roughly 58 mm of rain across the month.

The binding constraint here is rainfall and temperature — that is what rules months out, not any composite judgement. Rainfall is sharply seasonal: August averages 342 mm against 46 mm in February, so the wet season is the real planning constraint rather than heat or cold. May is the weakest month on these criteria.

April, October sit just outside the window — part of the month works and part does not. These are usually the interesting weeks: conditions are close to the peak-season answer while prices and crowds are not. The map lets you check them fortnight by fortnight rather than trusting a monthly average.

What northern Vietnam is known for

Ha Long Bay's roughly 1,600 limestone islands are a UNESCO site; Lan Ha Bay nearby is quieter
Hanoi's Old Quarter still organises streets by the guild that once worked them
Sapa's rice terraces are farmed by Hmong and Dao communities; they are greenest before the September harvest
Ninh Binh is called the inland Ha Long — the same karst, reached by rowboat through rice paddies
Northern Vietnam has a real winter, unlike the south; Sapa occasionally sees snow

Month by month

Month	High °C	Low °C	Precip mm	Wet days
January	18	12	58	11.7
February	20	13	46	11.3
March	24	17	69	14.1
April	27	20	134	15.5
May	29	22	215	20.9
June	30	24	258	22.1
July	30	24	314	24.5
August	29	23	342	26.4
September	28	22	276	21.9
October	26	20	160	15.8
November	23	16	61	10.7
December	20	13	50	9.0

Ticked rows are months where every hard requirement for a city trip is met across at least half the month.

By trip type

City	November to March
Hiking	November to March

Each row applies that trip type's own hard limits to the same climate data.

Open Northern Vietnam on the map →

View of Ha Long Bay from Queen Cable Car (49356763846) © Martin Lewison from Forest Hills, NY, U.S.A., CC BY 2.0 · cropped and resized · Wikimedia Commons

Hanoi, Vietnam © Linh Pham linharex, CC0 · cropped and resized · Wikimedia Commons

Nearby regions

Figures are 30-year climatology sampled at Hanoi, Ninh Binh, Sapa, Ha Long and Mai Chau, averaged across those locations, from ERA5-Land reanalysis fitted with a harmonic seasonal cycle and a trend term, evaluated for 2026. Sampling named towns rather than averaging the whole region avoids blending valley and mountain conditions into a figure true of neither. Cells are about 0.08° wide, from ERA5-Land's 0.1° grid, which is itself driven by a 0.25° (~28 km) atmospheric reanalysis — so individual valleys, sheltered bays and single summits are not resolved. In steep terrain read these as conditions for the wider area rather than for one village. They describe typical conditions, not a forecast. Read how the climatology is built.