Abstract: Tn this paper, correlations at intervals of 5-7 months are discussed in detail.Long range forecasting practice reveals an important phenomenon of correlations between predictands and predictors 5-7 months apart. In analyses of 500 hPa circulations, the correlation is the most significant in mid-and-high latitudes between winter and summer. Asia,the Pacific and Atlantic Oceans are the 3 key regions for this correlation in Northern Hemisphere. It is also found in ocean, possibly caused by air-sea interactions, partly.