Yiwu has a subtropical monsoon climate, mild and humid, with four distinct seasons. The annual average temperature is around 17 °C. July is the hottest month, when the average temperature is 29 °C (84 °F), the coldest month is January, reaching 4 °C (39 °F) on average. The average frost-free period in a year is 340 days. The annual precipitation is 1,100–1,600mm (43–63 in).
The best times for travel are spring and autumn, since every April and October sees the grand China Yiwu International Commodities Fair, and the weather is neither hot nor cold.
Spring begins in the end of March and continues to the end of May, lasting for about 60 days. Precipitation increases considerably compared to winter, sudden rains falling frequently. Bring an umbrella if you stay outside for a long time. Thin jackets and jeans are the perfect clothes. The average temperature is 18 °C (64 °F), which is good for shopping at the International Trade City. The International Commodities Fair is in April.
Summer is from the end of May to the end of September, lasting for 130 days. It is sunny and hot most of the time, with occasional afternoon thunderstorms. Typhoons attack the region mostly in this season. Except for the typhoons, it's good for outside activity. The average temperature is 25 °C (77 °F).
Autumn begins at the end of September, and continues to the end of November. Cool sunny days are common. The average temperature is 16 °C (61 °F). It is perfect for hiking and outside activity. The International Commodities Fair is October 21–25.
Winter is long, beginning in the end of November and ending in late March. The weather is dry, cold and windy, with occasional rain and snow. The average temperature is 6 °C (43 °F). It is a good time to stroll in the International Trade City. Do wear some warm clothes like sweater and coat if you need to do some outside activity.