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The delay of defoliation, the advance of blooming, in January, of some recently planted palm trees, the appearance of the housefly in winter, and the disappearance of the featuring cold and frost of Djelfa both prompted the need of a scientific explanation, based on the analyses of mean, minimum and maximum air temperatures records for a period of 40 years by the methods [coefficient of variation (CV), trend test, correlation and homogeneity test], which have shown that, although, the fluctuations of the mean temperature, especially in winter (CV = 27%), a global warming of 1 degrees C was recorded, more due to Tmin (1.4 degrees C) than to Tmax (0.92 degrees C). Summer was the most warming season, then autumn and finally spring. However, a slight cooling was in December and February, intermediated by January’s warming which would cause early break of the overwintering and the subsequent damages. Also, an almost recent abrupt change (of about 1 degrees C to 3 degrees C) was recorded except for winter, whose frost and cold disappearance would be partially caused by drought.