The coastal provinces from south to north and the capital cities of the most difficult and northernmost provinces in China.

The second question: Hainan Province, the southernmost province, is the capital of Haikou City.

Harbin, the capital of the northernmost Heilongjiang (border territorial waters), is either Changchun or Jilin.

Compared with Dongying weather, Haikou has a tropical monsoon climate, with an annual temperature of 15 and an average summer temperature of 30.

Harbin has a temperate monsoon climate. The lowest temperature in winter exceeds-10, and the average temperature in summer is about 20, with the same period of rain and heat.

Dongying belongs to temperate monsoon climate, with precipitation concentrated in summer, with the lowest temperature below 0 in winter and the average temperature around 25 in summer.

Among the three cities, Haikou has the most precipitation, Beijing has the largest annual temperature difference, and Haikou has the smallest.