3.1 Change in mean temperature and accumulated precipitation
During the period 1981-2011, the mean monthly temperature generally increased, especially in June (T6), July (T7) and September (T9) (Fig. 1). Affected by the monthly mean temperature, the mean temperature of different distribution patterns also increased with time. This was particularly the case for the periods January-June (T1-6), January-July (T1-7), May-September (T5-9) and June-September (T6-9) (Fig. 1). In contrast, monthly accumulated precipitation did not show any trend though time, but fluctuated between years. The accumulated precipitation from January to September (P1-9), June to September (P6-9) showed a decreasing trend from 1981 to 2011 (Fig. 1).