Frequent increases in temperature and related consequences have been the trending phenomenon for over ten decades, with a general rise of about 0.740C. This study evaluates the effects of different percentage covers of tree canopies for outdoor thermal improvement of campus areas in Bauchi, Nigeria. Firstly, the study involves on-site measurement of existing features on the site and the climatic conditions. Secondly, performing simulation for evaluation of the plant-surface-atmosphere interactions with Envi-met Version 4.4.2. The vegetation effects were evaluated for outdoor air temperature and mean radiant temperature (MRT) reduction. It is found that the maximum air temperature reduction of 3.380C and 24.240C of MRT were achieved with up to 45% tree canopy coverage. The mean air temperature and MRT reduction of 0.630C and 4.800C were respectively achieved with the same percentage coverage of the canopies. However, it was found that the thermal reduction effects of vegetation do not apply to every hour of the day. In essence, proper planning and implementation of campus outdoor spaces is the key factor in improving its thermal conditions. Thus, adhering to the practical recommendations bring a significant improvement in ameliorating the rise in atmospheric temperature on campus outdoors.