Lhasa lies in a small basin and the topography is plain. The climate of the city is mild, without severely cold winters or extremely hot summer. It has highland temperate semi-arid monsoon climate. Being a high-altitude city, the air is thin, and temperatures vary greatly within one single day. The average yearly temperature is about 8 °C (46 °F). There is plenty of sunshine all year round, with annual sunshine time reaching 3,000 hours. It is easy to get sunburn in Tibet because of strong ultraviolet radiation. Make sure that you bring your sunglasses, sun cream, hat or umbrella with you.
The annual precipitation is 500 mm (20 inches), with rainfall concentrating from July to September, but the rainfall usually happens at night and it is still sunny during the day. Temperatures generally drop suddenly after sunset. Due to the variation of weather conditions, prepare a variety of clothing. The best time to travel around Tibet is between April and October, and the peak season is from May to September.
Spring is from March to May. It begins to warm up, but there are still alternative low temperatures. It is sunny, dry and windy. Long-sleeve shirts, light sweater and jackets should be prepared.
Summer is from June to August. It is sunny and relatively humid with some rainfall. There is big difference of temperature before and after sunrise, from hot to chilly. Prepare summer clothes, but also prepare jacket or sweater for variation of weather. Summer is the season filled with many festivals and celebrations. See Lhasa festivals and events.
Autumn is from September to October. It is one of the best seasons for traveling in Lhasa, with the weather being pleasantly mild and relatively humid with some rainfall. Prepare long-sleeve shirts, sweater and overcoat.
Winter is from November to February, with dry and windy weather. The sun often shines high and bright in winter. Much fewer people visit Lhasa in winter. Actually Lhasa has no severely cold winters if you look at the record winter temperatures. Prepare winter clothes such as down jackets, pullovers and sweaters. Sun protection, moisturizer and lip balms are advisable because of the strong sun and dry weather.
Winter is considered the low tourist season, so the hotel and tour rates are cheaper than usual. Getting train tickets to Lhasa is also much easier than in summer.