Abstract:In order to investigate the observational basis of the climate predictability, with the detrended fluctuation analysis (DFA) the long-term variations of the temperature and the precipitation in Beijing have been investigated. Non-scaling exists widely in the nature system, including the climate system; one of its features is a power function existing in an observable quantity, which represents the complex of the climate system. Based on the DFA, the calculations for daily temperatures and precipitations during 2003 were conducted, and it is found that there are several ranges where their scaling is unchangeable; in the specific ranges, the time series of the temperature and the precipitation exhibit a positive long-term correlation feature, that provides a theoretical basis for climate predictions.