season creep
noun [ U ] uk/ˈsiː.zən ˌkriːp/ us/ˈsiː.zən ˌkriːp/
季节蠕变（在一些国家，季节并不象过去一样明显或有规律地变化，这可能是全球变暖引起的）
the fact that in some countries seasons do not change as much or as regularly as they did in the past, thought to be caused by global warming (= the fact that the earth is becoming warmer)