Abstract: Based on monthly cloud cover observation data from 20 global exchange stations of five provinces (Henan, Hubei, Hunan, Anhui and Jiangxi province) in central China during 1959-2005, the seasonal/annual variation and regional distribution of total cloud cover in last 47 years were analyzed. The results showed that both of average annual and seasonal total cloud cover in central China decreased in last 47 years. Variation of total cloud cover changed among different regions, and there were two kinds of typical space-time distribution. One was positive variation for both annual and seasonal, and increasing from south to north. Its center located in the northern middle part of central China. The cloud cover of spring and autumn declined and there was no obvious change in summer and winter from 1959 to 2005. The other was reverse variation on the two sides of the Yangtze river, obvious in annual variation.

Key words: Cloud cover, Variation trend, Change, EOF