On July 31, Han Lei got up around 5 am to harvest watermelons with his father and load them on a truck.

After a four-hour ride, the 12-year-old arrived in Zhengzhou, capital of Henan province, to start his first summer holiday in a big city as a street vendor.

Han and his father traveled nearly 160 kilometers to Zhengzhou as the watermelons his grandfather grows fetch much higher prices there than in their hometown in Kaifeng, known for its high yield of the fruit.

Han Lei helps his father sell watermelons on a street in Zhengzhou, Henan province, July 30, 2013. [Photo by Wang Zhenzhen for China Daily]

"Cities are beautiful but the only problem is that there are too many cars moving fast," Han said. "I want to live in an urban area when I grow up."

Han's father told his son how to read traffic signals and urged him to be extremely careful when crossing roads.

Han, who will start sixth grade in a rural primary school after the holiday, is a good helper for his father as he can independently weigh the melon a customer selects, count money and give change.

Han's father, Han Bin, a divorced migrant worker, has worked on construction sites for more than six years to feed his three children. However, he gave up manual work temporarily after seeing several workmates get sunstroke each day in this scorching summer.

The 43-year-old said his family lives in a makeshift shelter in an underground passage but it was a bad choice as it attracts many mosquitoes after torrential rain at night.

Their watermelon sales while in the city were not good either as they had to move their truck from time to time to avoid surprise inspections of chengguan, or urban patrol officers.

Wang Zhenzhen in Zhengzhou contributed to this story.