Het weer in Guilin (Yangshuo) in september

September reports here are good - one regular calls the weather glorious and the first half of the month still green across the terraces - but the practical advice is about the river rather than the sky. The Li cruise can lose part of its route to low water, and the level is at its worst from January to March, so September is on the safe side of that; even so they suggest booking the boat only a day or two ahead, so a bad forecast or a short river does not strand a fixed ticket. October is the month they rate above this one. Our row is hot: 33C reading as 37C over 22.8C nights, with 74.3mm across 11.3 days. The record: humidity 74 percent, 9.3 hours of sun and AQI 60.

Regulars are specific this month runs colder than December, the low season here meaning real savings and thinner crowds despite temperatures that can still feel pleasant whenever the sun actually breaks through. Our row backs that cold, genuinely wet read, 14.2C over 5.9C nights feeling as low as 3C, with a substantial 98.6mm of rain across 13.5 days and a trace of early snow. Regulars are consistent the surrounding rivers make the cold feel more penetrating than the number alone suggests, thick coats, scarves and real layers the standard advice throughout. This remains genuinely drier than Guilin's own summer wet season even with real rain still a common feature day to day. The record: 4.7 hours of sun, humidity 73 percent and AQI 90.

Regulars describe a genuinely changeable transition month, mostly cloudy and windy with persistent light drizzle rather than heavy downpours, and are specific that the area's wet climate makes the air feel colder than the actual temperature - a thick padded coat and a heavy wool sweater are standard advice even though the numbers alone might not suggest it. Our row backs the damp chill, 15.3C reading as 14C over 7C nights feeling 4C, with a substantial 116.9mm of rain across 14.3 days and just 4.3 hours of sun a day, among the lowest sunshine figures in this project. The record: humidity 76 percent, a 12.9 kph wind and AQI 72.

December in Guilin is cold, damp and often foggy - regulars quote 7 to 15C and sometimes as low as 3, against our row's 15.7C day over a 6.3C night that reads as 4C - with 6.2 hours of sun a day, among the greyest in this collection. Two pieces of advice they repeat are worth more than the temperature. First, book a hotel with proper heating: much of southern China has none, and this is the month you notice. Second, the Li River cruise is shortened in winter because the water is low, so operators bus you downstream before boarding and the run is about a third shorter, with the karst scenery less dramatic than the photographs. Against that: fewer visitors and lower prices. The record: 51.8mm across 8.7 precipitation days, humidity 69 percent, a 13 kph wind and AQI 88.

November is among the months Guilin regulars recommend - autumn, comparatively little falling, and the maples at Gudong and the ginkgos at Haiyang turning - with the note that it only turns properly cold towards the end of the month. Mist and haze are part of the appeal here rather than a spoiled view: they halo the karst and are what most people are photographing. The practical warning concerns the river. November is low water on the Li, and posters report the cruise boat scraping bottom and the trip taking an extra half hour; the smaller rivers around Yangshuo stay fine for drifting. The record: 22C days, 12.3C nights, 10.7 precipitation days and only 6.1 hours of sun a day, AQI 69.