Xi'an weather and climate: what to expect each month

Xi'an sits on the southern edge of the Loess Plateau with a continental, semi-humid climate — four seasons, sharply drawn. Winters (December–February) are cold and dry, with January lows averaging around −5°C. Summers (June–August) are hot, humid and wet, with July highs averaging 32°C and most of the year's rain. Spring and autumn are short, mild, and the reason most travellers come.

The weather itself rarely makes or breaks a Xi'an trip. Winter air quality is worth a mention — the city sits in the Fenwei Plain, one of China's three priority pollution-control regions, and heating season can still bring hazier days — but the trend is firmly in the right direction: 2025 delivered a record 274 good-air days and the first-ever annual PM2.5 below 40 µg/m³. For the full when-to-go call (weather, crowds and holidays together), see our best time to visit guide.

Spring (late March–May). The city warms fast — March days reach around 14°C, May 26°C — and the blossom season (cherry, peach, crabapple) opens in April. It's one of the two best windows, with one catch: spring winds can carry dust in from the Mongolian and Inner Mongolian plains, especially in March and April, and occasionally thicken into a full sandstorm that turns the sky yellow for a day or two. Xi'an gets these far lighter than Beijing, but they happen. Wear: layers — a T-shirt with a light jacket or hoodie, something warmer for March mornings, and a mask plus sunglasses for dusty days.

Summer (June–August). Hot, humid and rainy. July averages 21–32°C, sunny days routinely top 35°C, and 40°C is on record. July and September are the year's two rainiest months, each with around ten wet days, so the heat turns muggy rather than dry. Plan the day around it: sights at opening time, air-conditioned museums at midday, the city after dark. The upside is the air — summer is Xi'an's cleanest season. Wear: light, breathable cotton or linen, a hat and sunscreen, and a compact umbrella or rain shell for afternoon downpours.

Autumn (September–early November). Many residents' favourite season. September runs 16–25°C (still rainy), October a crisp 10–20°C, and the ginkgoes turn gold in late October. Skies clear, the air stays relatively clean, and crowds thin after the October holiday. Wear: layers again — T-shirt and light jacket, moving to a sweater or light coat by November — and keep the umbrella through September.

Winter (December–February). Cold and very dry. Daytime highs sit around 5–8°C, nights fall below freezing, and rain is rare — but the official heating season runs November 15 to March 15, and coal burning makes this the worst air-quality window of the year (more below). Snow is occasional rather than expected. In exchange you get the year's thinnest crowds and lowest prices, plus the Spring Festival lantern fair on the City Wall around Chinese New Year. Wear: a real winter coat (down if you run cold), warm layers, gloves and a hat, plus an N95 or KN95 mask for bad-air days — which doubles as cold-face protection.

For the full kit, see our packing list.

Average daily high and low in °C, rainfall, and air quality. Temperature norms align with TravelChinaGuide and Weatherspark; the air-quality column is qualitative (see the next section for the numbers behind it).

Month	High / Low (°C)	Rain	Air quality
January	5 / −5	Very low	Poor — heating-season peak
February	8 / −2	Very low	Poor — heating season
March	14 / 4	Low	Improving; heating ends mid-month; sandstorm risk
April	21 / 10	Moderate	Moderate; occasional spring dust
May	26 / 14	Moderate	Moderate
June	31 / 19	Moderate	Good
July	32 / 21	High (rainiest)	Good
August	32 / 21	Moderate–high	Good
September	25 / 16	High (rainiest)	Good
October	20 / 10	Moderate	Good — a clean, crisp month
November	12 / 3	Low	Declining; heating starts mid-month
December	6 / −4	Very low	Poor — heating-season peak

Two notes: daily temperature swings run around 10°C year-round, so spring and autumn mornings are colder than the averages suggest. And the rain figures are about frequency more than intensity — summer storms can be short and torrential, while winter „rain” is barely worth the name.

Xi'an's air has improved steadily for a decade, and the numbers now show it. 2025 was the city's best year on record: 274 good-air days (the most ever), PM2.5 averaged 39.5 µg/m³ — the first year below 40 — and PM10 met the national standard for the first time. The city sits in the Fenwei Plain, one of China's three priority pollution-control regions, and the gains come from a sustained programme: coal-fired boilers shifted to natural gas, industry controls, and the winter-heating management that Beijing now benchmarks across northern cities.

What's left is seasonal. The official northern-China heating season runs November 15 to March 15, and on still, cold days the winter inversions can still trap haze over the plain — December and January are the haziest months, typically running two to three times the summer level, and short severe episodes can push the daily AQI above 150. In summer and autumn the air is genuinely good, often comparable to any big Chinese city.

Practical takeaways:

• May–October is the cleanest window, and spring–autumn is the sweet spot for temperature too.
• In winter, check the AQI daily. aqicn.org and IQAir both carry real-time Xi'an readings. If it climbs past 150, shift outdoor sights to a clearer day and spend the afternoon in museums, malls or on the metro — Xi'an's indoor depth is exactly why winter visits still work.
• Carry an N95 or KN95 mask in winter; it's standard local practice on hazy days. Travellers with asthma, heart conditions or pregnancy should treat winter PM2.5 as a real factor — see our health and safety notes.

Weather is only half the planning story in Xi'an; the Chinese holiday calendar often matters more. The trade-offs are real but manageable — summer pairs the cleanest air with the school-holiday crowds, while winter pairs the haziest weeks with the year's emptiest sights.

A few rules of thumb:

• Best overall: late March–May and September–early November — mild days, reasonable air, and you sidestep both the worst heat and the holiday crowds. Full reasoning in best time to visit.
• Avoid the holiday peaks regardless of weather: National Day Golden Week (October 1–7), May Day (around May 1–5) and Chinese New Year (late January or February). Exact dates and survival tactics are in our public holidays and crowds guide.
• If winter is your only option: aim for the weeks right after a major holiday (mid-January, late February) for the thinnest crowds, pack for cold, and keep your itinerary flexible enough to swap an outdoor day for museums on a hazy day.