Spring and autumn are the answer nearly every guide gives for Hangzhou, and both are right for different reasons — and incomplete for different reasons too. Spring carries the tea harvest and the causeway blossom that make the lake worth photographing, but it is also the wettest stretch of the year by total rainfall, wetter than autumn by a wide margin. Autumn is drier and clearer, but the first week of October is Golden Week, and Golden Week at West Lake is not a crowd in the ordinary sense — it is a capacity event at a park with no gate to limit entry. A useful answer to “when should I go” has to hold both of those facts at once, plus a third one most coverage smooths over: September specifically is not a dependable shoulder month. Current rainfall figures for the month disagree by more than double depending on the source, and that disagreement is itself the honest finding — the month runs on typhoon behaviour that varies year to year, not a fixed seasonal pattern.
Checked 28 Aug 2026 Climate framing and the September rainfall disagreement (roughly 79 mm against roughly 200 mm depending on source) cross-checked across weatherspark.com, climate-data.org, chinahighlights.com and chinadiscovery.com.
The month-by-month numbers
Hangzhou runs a humid subtropical climate with four distinct seasons rather than a simple wet-dry split. Average annual rainfall sits around 1,450 mm and relative humidity stays in the 72–80% range for most of the year, which shapes how a visit feels as much as temperature does. The table below is the planning reference; the season-by-season notes that follow go into what each stretch is actually good, or bad, for.
Checked 28 Aug 2026 Annual averages and month-by-month temperature and rainfall figures compiled from weatherspark.com, climate-data.org, chinahighlights.com and chinadiscovery.com, cross-checked; source variance is flagged where it appears.
| Month | High / Low | Rainfall | What’s happening |
|---|---|---|---|
| January | 8.3°C / 1.8°C | — | Coldest month; rare light snow; indoor spaces largely unheated |
| February | ~9°C / ~2°C | — | Still cold; Chinese New Year travel crowding, separate from Golden Week |
| March | ~14°C / ~7°C | ~138 mm | Spring begins; willow catkins and early peach blossom on Su Causeway |
| April | ~20°C / ~13°C | ~147 mm | Peak spring bloom; prime window for Mingqian Longjing tea picking |
| May | ~26°C / ~18°C | ~147 mm | Still comfortable, but humidity climbing toward summer levels |
| June | ~30°C / ~23°C | Highest rainy-day count, ~15.4 days | Meiyu (“plum rain”) season begins, runs into early July |
| July | 33.6°C / 25.2°C | — | Hottest month; humid, sometimes topping 38°C |
| August | Similarly hot and humid | — | Typhoon season (Aug–Sep); real storm-disruption risk |
| September | — | ~79 mm to ~200 mm, sources disagree | Genuinely unpredictable; osmanthus blossom starts late in the month |
| October | — | ~72 mm | Dry, clear autumn stretch begins — except October 1–7, Golden Week |
| November | Autumn range roughly 25°C down to 14°C across Sep–Nov | — | Among the driest, clearest months; good for walking and photography |
| December | 11.3°C / 3.7°C | Lowest humidity of the year, ~72% | Cold and damp indoors; Impression West Lake shuts down for the season |
Spring (March–May): the bloom and the tea come with the year’s heaviest rain
April is the postcard month — peak bloom along the causeways and the Mingqian harvest window at the Longjing tea terraces, the picking period before the Qingming Festival in early April that produces the highest-graded tea and coincides with the terraces looking their best, workers visibly out among the rows. Reaching the villages themselves, and what to watch for once you’re there, is covered separately — see things to do in Hangzhou for the route and a documented tea-house scam worth knowing about before sitting down for a tasting.
Checked 28 Aug 2026 Longjing picking calendar and Mingqian harvest timing from municipal and travel-guide sources, cross-checked 28 Aug 2026.
The trade-off is rain. March, April and May each average 138–147 mm, which makes spring wetter than autumn’s driest months by a wide margin — October runs about half of April’s total. None of the three spring months is a washout, but pack for it, and don’t read “spring is best” as “spring is dry,” because those are two different claims. The pattern isn’t unique to this city, either: Suzhou, in the same climate band, runs a comparably wet spring calendar, so shifting a trip there instead doesn’t dodge the rain, only the specific crowds — see Suzhou.
Checked 28 Aug 2026 Monthly rainfall comparison (spring months vs. October) from weatherspark.com and climate-data.org, checked 28 Aug 2026.
If the trip is built around the tea-and-shrimp dish that shows up on nearly every Hangzhou menu, Longjing shrimp makes the most sense in spring simply because the fresh-leaf tea it’s finished with is closest to harvest — see what to eat in Hangzhou for where to get it and what it costs.
Summer (June–August): the season to route around
June is the wettest month of the year by rainy-day count, averaging roughly 15.4 rainy days as part of the Meiyu (“plum rain”) season that runs from mid-June into early July — persistent grey skies and saturated air rather than dramatic storms, but relentless. July follows with the year’s hottest average high, 33.6°C, and lows that don’t drop below 25.2°C, so the heat doesn’t really break overnight. August stays similarly hot and humid and layers typhoon season on top, running through September, meaning occasional real storm disruption rather than a remote possibility. Nothing in the research for this city points to a summer-specific draw strong enough to offset that — no headline bloom, no festival tied to these three months — so if travel dates are flexible at all, this is the stretch to move away from rather than tough out.
Checked 28 Aug 2026 June rainy-day average, July high/low, and August typhoon-season framing from weatherspark.com, climate-data.org and chinahighlights.com, cross-checked 28 Aug 2026.
Autumn (September–November): the more reliable window, with one exception
On the numbers, late September through November is the steadier of the two shoulder seasons. October rainfall drops to roughly 72 mm, well under half of any spring month’s total, and November sits among the driest, clearest stretches of the year — the kind of weather that makes walking the Su Causeway or climbing around Feilai Feng actually pleasant rather than just tolerable. Osmanthus (sweet olive) blossom begins in late September and carries into October, filling the city with its characteristic sweet fragrance — a genuine seasonal draw that isn’t attached to a single ticket or a single sight, unlike the spring bloom’s concentration along the causeways.
Checked 28 Aug 2026 October and November rainfall and clarity, and osmanthus blossom timing, from chinahighlights.com and chinadiscovery.com, checked 28 Aug 2026.
One set of sources puts September rainfall around 200 mm, tied to lingering typhoon influence; another puts it around 79 mm, in line with a “drying out” autumn story. Both figures come from credible current sources, and the gap is too large to be a rounding error — it more likely reflects real year-to-year volatility, since the month sits inside typhoon season. Treat September as unpredictable rather than reliable, and build slack into plans that land there, rather than assuming it behaves like October.
Checked 28 Aug 2026 September rainfall disagreement documented across current climate sources, checked 28 Aug 2026; not resolved to a single figure because the sources themselves don’t agree.
Golden Week (October 1–7): why this specific week gets a hard no
West Lake recorded more than 7.5 million visitors over the seven days of the October 2024 holiday, averaging over 500,000 a day and peaking above 800,000 on the busiest single days. That volume matters more here than at most Chinese attractions because the lake itself has no gate and no hard capacity limit — unlike a site that can simply stop selling tickets, West Lake keeps absorbing people. Traveller reports describe the lakeside path becoming genuinely single-file and the Broken Bridge, one of the classic lake views, effectively impossible to actually see because of the number of people standing on it. This crowding stacks two separate sources of demand on the same week: the domestic Golden Week travel surge, and Hangzhou’s existing role as an easy day trip from Shanghai — covered in more detail at the Hangzhou–Shanghai train guide — both landing on the same unticketed park at once.
Checked 28 Aug 2026 2024 Golden Week visitor figures (7.5 million over seven days, 500,000+/day average, 800,000+/day peak) from SCMP and Tripadvisor visitor reports, cross-checked against Hangzhou tourism reporting, 28 Aug 2026.
If Golden Week dates are unavoidable, the honest planning move is to treat West Lake itself as something to see at the edges of the day — early morning, before the day-tour buses arrive — rather than expect a normal midday visit, and to weight the trip more toward ticketed, capacity-managed sights than toward the open shoreline.
Winter (December–February): cold, quiet, and one show goes dark
December averages an 11.3°C high and 3.7°C low, with the year’s lowest humidity at roughly 72%, and January is colder still at 8.3°C/1.8°C with occasional light snow. The genuine complaint worth knowing about ahead of time, not after arriving, is that there’s no widespread central heating south of the Huai River line, Hangzhou included — indoor spaces, some hotels and restaurants among them, can feel damp-cold in a way that surprises visitors used to heated buildings further north or in Western climates. February adds its own crowding, tied to the Chinese New Year travel period, which runs on a different calendar than Golden Week and is worth checking separately if travel dates land near it.
Checked 28 Aug 2026 December and January temperature/humidity figures and the unheated-buildings note from weatherspark.com, climate-data.org and chinahighlights.com, checked 28 Aug 2026.
The nightly lake-stage show closes annually from mid-December through January for maintenance and weather, and even in season it’s fully weather-cancellable — rainstorms trigger a refund, and standard seating gets disposable ponchos rather than a cancellation for lighter rain. A winter trip built around catching the show on a specific night is planning around something that may simply not be running.
Checked 28 Aug 2026 Impression West Lake’s seasonal closure and weather-cancellation policy from chinadiscovery.com, tripadvisor.com and traveloka.com, cross-checked 28 Aug 2026.
Timing a trip around one specific thing
A few dates on the calendar are worth planning around directly rather than just picking a season.
| Event | Timing | Note |
|---|---|---|
| Mingqian Longjing tea harvest | Picking runs late March–early November; prized harvest is just before Qingming Festival, early April | Terraces look best with pickers visibly working the rows |
| Osmanthus blossom | Late September into October | Citywide fragrance, not tied to a single paid sight |
| Qiantang River tidal bore, peak viewing | Around the 18th day of the 8th lunar month, roughly mid-September | A three-day “Tidal Bore Enjoying Festival” window; waves rise 1–1.5 m, best viewed from Six Harmonies Pagoda |
| Golden Week | October 1–7 | Avoid outright, or plan around the edges of each day |
| Impression West Lake closure | Mid-December through January | Show unavailable regardless of other plans that week |
Checked 28 Aug 2026 Tidal bore festival window and wave height from travelchinaguide.com; other dates cross-referenced against sources cited earlier in this article, checked 28 Aug 2026.
The tidal bore date pairs naturally with the Six Harmonies Pagoda day laid out in the 4-day Hangzhou itinerary, since the pagoda is one of the better vantage points on the river and the viewing window is short and specific enough to be worth checking before booking flights. The same seasonal logic — spring bloom against autumn clarity, with Golden Week as a hard exception — carries over to the water towns and hill towns outside the city, worth keeping in mind whichever season the rest of the trip lands in.
Put plainly: if the causeway bloom and the tea harvest matter more than dry pavement, go in April and accept the rain. If clear skies and comfortable walking matter more, aim for late September through November and skip the first week of October entirely. Either choice beats summer, and neither one requires guessing — the numbers above are what to check against whatever dates are actually on the table. None of this changes the basic shape of a Hangzhou trip, laid out at the Hangzhou hub — it just changes which version of the lake shows up: crowded and blooming, quiet and grey, or clear and fragrant.
Summarised from public traveller discussion, not from a visit. We have not travelled this route ourselves — see how we check.