Talking about the Phase without Frost
People usually call the last frosts of spring the “final frost” and the first frosts of autumn the “first frost”. The phase without frosts refers to the period between the “final frost” and “first frost.”

Due to China’s huge size, the length of the phase without frost varies from province to province. Most parts of China lie in the North Temperate Zone, so frost happens in all parts of the country except some parts of Hainan Island, Yunnan Province, Taiwan Province and the islands in the South China Sea. According to statistics, the “first frosts” appear in mid-September in Northeast China and the “final frost” happens in late April. The phase without frost lasts less than 150 days. For the North China areas, “first frost” happens in late October and the “final frost” in early April, with a 200-day phase without frost in between. The phase without frost is about 250 days long in the Yangtze River regions and more than 300 days long in South China.

The duration of the phase without frost is related to the length of the cold season in the area. In other words, places with long cold seasons also have long phases without frost.