The objective of this research study was to investigate the effect of inlet water temperature on drip irrigation system uniformity. The experimental work was held under laboratory conditions, whereas a model for a drip irrigation system was used to follow the effect of increased irrigation water temperature on uniformity parameters. The variables of this study were water temperature (T) with five levels namely 20, 25, 30, 35, and 40 °C three operating pressure heads (H) which were 10, 15, and 20 m of water with two types of emitters named A and G. Uniformity parameters under study included uniformity coefficient (UC), emission uniformity (EU), Manufacturing coefficient of variation (CV), and emitter flow rate variation (qavr). The results showed that increasing inlet water temperature will lead to mean flow rate for both emitters at all pressure heads. The increase in water temperature led to improve the uniformity levels of drip irrigation system for both emitter types. The two emitters' drip lines showed different response for the operation heads as the best performance for G emitter laterals was at 20m head while it was 10m for A emitter. Effect of water temperature on uniformity was clear as it improved the corresponding classification for both UC and EU with the two emitters' drip lines. T40 is recommended for the two emitters types. The effect of high levels of water temperature on plants should be deeply investigated to avoid the negative possible ones.