Hangzhou has a subtropical monsoon climate, mild and humid. Spring is warm and humid. Summer is hot with lots of rain. Autumn is cool. Winter is cold and dry, sometimes with snow.The average annual temperature in Hangzhou is 17 °C (62 °F). Average annual precipitation is 1,141 mm (45 inches), and average humidity is 76%. The average annual sunshine totals 1,765 hours.
Hangzhou's air quality is generally good. The average AQI (Air Quality Index) in Hangzhou is 66 (An index value between 0 and 100 means good; over 100 means polluted.)
The coldest month in Hangzhou is January, with an average daily high of 8°C (46°F). The hottest month is July with an average daily high of 34 °C (92 °F). The driest and rainiest months in Hangzhou are December and June, respectively.
Best Time to Visit Hangzhou
Hangzhou is suitable for travel all year round, but the most pleasant and popular seasons to visit are spring and autumn. Spring sees the most beautiful scenery around West Lake, with peach blossoms and budding willows. The lake is clear blue and shines in the sun.
Autumn sees the best weather. Comfortable temperatures and relatively dry weather will give you a pleasant tour experience.
Spring — warm and pleasant
Spring is from March to May in Hangzhou. The weather warms up and becomes gradually more humid, but with frequent and sharp changes of temperature and weather conditions. The average daily high and low temperatures are 25°C (77°F) and 14°C (57°F), respectively. Spring is a humid season, with drizzle. The average total precipitation is 409 mm (16 inches). Spring is the best season for a visit to West Lake. The peach blossoms on Su Causeway right across West Lake enhance the lake, making it enchanting. It sometimes drizzles in spring. The lake, water towns and city itself are shrouded in misty rain, adding misty and subtle colors.
Summer — hot and humid
Hangzhou Summer is from June to September, it is hot and rainy. Most rain falls between mid-June and mid-July, when rain and drizzle seem continuous. Average temperatures are usually above 34°C (86°F), and sometimes the highest temperature reaches up to 40°C (104°F). June and September are the rainiest months with 200 mm (7.8 inches) in each. Rainfall builds up in preceding months and tails off sharply afterwards. In August or September, Hangzhou is occasionally hit by typhoons, which account for the 'second rainy season'. The average humidity in summer in Hangzhou is 80%. Summer is the wettest season of the year.
Wear any summer clothes, such as shirts, shorts and skirts. You are recommended to prepare sunglasses, hats, and umbrellas, and to drink lots of water.
It is very relaxing to visit the nearby water towns in summer, such as Nanxun,Xitang and Wuzhen. During the Chinese Mid-Autumn Festival in September, osmanthus blossoms are in full bloom, creating fragrance all round the city.
Autumn — best weather
Autumn is from October to November. The autumn in Hangzhou is short. Its pleasant dry and cool weather makes it the best time of year to visit Hangzhou. The average high and low temperatures are respectively 23°C (73°F) and 14°C (57°F) in October, and 18°C (64°F) and 9°C (48°F) in November. Rainfall decreases in autumn. There is a total of about 131 mm (5 inches) of rain in October and November.The average humidity in autumn is 75%.
If you come in autumn, don't miss the Mid-Autumn Festival. 'Three Pools Mirroring the Moon' on West Lake is the best moon-viewing spot in all of China.
Winter — cold and humid
Winter is from December to February of Hangzhou. Winter is cold, at just above freezing on average, with high humidity, and it snows sometimes. January is the coldest month with temperatures dropping as low as -3°C (26°F). Average low and high temperatures are respectively 2°C (37°F) and 11°C (51°F) in December, 0°C (33°F) and 7°C (46°F) in January, and 2°C (35°F) and 9°C (48°F) in February. The average total rainfall in winter is 207 mm (8 inches). It rains least in December while rainfall increases slightly in January and February. The average humidity in winter in Hangzhou is 75%. December is the driest month of the year. Prepare sweaters and down jackets for winter. Winter is low season in Hangzhou, so it is less crowded. It is a good time to visit if you prefer a quieter experience.