Global and local models of climate change indicate that in many parts of the Arabian Peninsula rainfall increments are expected during this century. The Kingdom of Saudi Arabia (KSA) is also subject to rainfall increases especially in the northern and southwestern high mountainous parts with some local increments and decrements in some other parts. Such impacts are very important, because they are bound to affect also the infrastructure in the urban areas and also engineering water structures such as dams, reservoirs, levees, culverts, flood protection canals, groundwater recharge, etc. So far, in almost all water-related application projects, the possible impact of climate change has not been taken into consideration. It is the main purpose of this paper to develop suitable preliminary climate change indicators in terms of trend component technique and expose its applications throughout the historical annual daily maximum rainfall records. Trends in the past records are implementations of future possible tendencies in other words they are helpful as preliminary descriptors of possible trends.