Table 1 Sample information

Edge of tropical

Wenchang

19.57°N, 110.80°E

33

25

8

Wanning

18.81°N, 110.39°E

21

16

5

Haikou

20.02°N, 110.20°E

33

21

12

Qiongzhong

19.04°N, 109.83°E

18

10

8

Sanya

18.25°N, 109.51°E

37

22

15

Jinghong

22.01°N, 100.77°E

34

23

11

Dehong

24.43°N, 98.59°E

21

19

2

South subtropical

Nanning

22.82°N, 108.36°E

25

17

8

Foshan

23.02°N, 113.11°E

12

10

2

Guangzhou

23.41°N, 113.23°E

33

19

14

Jiangmen

22.50°N, 113.40°E

5

2

3

Zhongshan

22.40°N, 112.72°E

20

12

8

Fuzhou

26.08°N, 119.30°E

24

18

6

Xiamen

24.59°N, 118.10°E

24

15

9

Mid-subtropical

Changsha

28.21°N, 112.99°E

25

11

14

Chenzhou

25.77°N, 113.01°E

18

13

5

Nanchang

28.68°N, 115.86°E

22

16

6

Chengdu

30.66°N, 104.07°E

18

14

4

Nanchong

30.49°N, 106.04°E

2

1

1

Chongqing

29.57°N, 106.55°E

24

24

24

North subtropical

Hefei

31.82°N, 117.23°E

9

8

1

Nanjing

32.05°N, 118.79°E

27

20

7

Shanghai

31.23°N, 121.48°E

31

24

7

Wuhan

30.35°N, 114.17°E

6

2

4

Wuxi

31.34°N, 120.18°E

3

3

0

Hangzhou

30.18°N, 119.5°E

26

18

8

Warm temperate zone

Beijing

39.77°N, 116.66°E

30

24

6

Shangqiu

34.17°N, 116.20°E

13

13

0

Taiyuan

37.98°N, 112.32°E

31

31

0

Xian

34.17°N, 108.21°E

18

18

0

Tangshan

39.96°N, 118.81°E

3

2

1

Kaifeng

34.80°N, 114.27°E

15

12

3

Tianshui

34.71°N, 105.47°E

22

20

2

Dalian

38.94°N, 121.40°E

21

15

6