Xi'an (Xian) weather in September

Regulars are specific this counts as one of the best months to travel across China generally, though mid-October specifically can turn cooler with genuinely possible wet weather, a woolen sweater and heavy jacket the standard advice by that point. Our row backs that mild, genuinely wet and hazy read, 18.3C over 11C nights feeling 9C, with a substantial 97.9mm of rain across 12.8 days and real haze building through the month. Regulars are consistent both Xi'an and Beijing are prone to real fogginess in the second half of the month on top of the cold setting in, though other visitors report pretty autumn leaves and no real rain issue during their own trips. The record: only 5.9 hours of sun, an 8.5 kph wind and AQI 123.

May, September and October are the months regulars put first for this part of China, and March is the one just after winter - early blossom in the parks, and visitors who remember cold, rain and even a little snow at the warriors. Our row reads 16.6C by day feeling 15C, 6.6C at night feeling 4C, with 0.6cm still in the snow column and only 31.8mm of rain across 5.5 days. Dry air too, 55 percent with a dew point of 1.3C, so the shade bites. The site is largely under cover but the walk between the pits is not. The real cost of the season is the air at AQI 126. The record: 8.5 hours of sun and a 9.6 kph wind.

Asked when to come, the Xi'an forum answers April and May, the pair regulars rate as the best stretch for travelling anywhere in China - April described as very comfortable with the blossom fully out, where May can already run warm. The practical advice attached to it is about timing the Terracotta Army rather than the season: about 40 minutes out from Xi'an railway station, roughly two hours to see the whole museum, and go early, since it opens at 08:30 and the first hour is the quiet one. The record for April: 22.2C days, 11.5C nights, 8.1 precipitation days and 55.8mm, humidity near 56 percent, 8.8 hours of sun - and AQI 112, the one number the forum does not raise.

Forum regulars call November a genuinely good stretch for Xi'an, with fewer crowds at the Terracotta Warriors than peak season and fall foliage still turning in early November. Temperatures drop noticeably across the month though: early-to-mid November runs roughly 5-15C, but by late November that falls to 0-7C by day and near freezing overnight. Rain isn't flagged as a real concern for the month - the main planning factor posters raise is simply how much colder the back half of November gets compared to the front half, so exact travel dates within the month matter more than usual.