Abstract: Background and Objectives: The contrariety between recent observed and simulated trends in a global climate warming has inspired a debate about conceivable events and indications for future climate fluctuation projections. Nonetheless, little has been said in this discussion in regards to observed and simulated trends of temperature and relative humidity as these two features contribute extensively to the warming earth. The present study aimed to evaluate and model seasonal fluctuation of observed air temperature and relative humidity in East London, Eastern Cape South Africa. Materials and Methods: The historical data of temperature and humidity were obtained from the South African Weather Service and analyzed through the ordinary least square regression model in Gretl statistical software. Results: The study investigated trends patterns in temperature, relative humidity and appraises the relationship between the observed and simulated temperature and relative humidity in the course of recent decades (1986–2016), the trend also predicted for the next 14 years (2017-2030). The observed, modeled and future trend patterns of temperature and relative humidity were produced using statistical analysis. In general, the simulated trends fall within the observed range of trends (95% confidence interval), with better consistency for the longer period. Seasonal trend patterns contrast for the seasons, with the autumn and summer exhibiting perpetual positive trends across the decades and spring and winter season exhibiting a coherent cooling pattern across the study years that has developed in the recent years and this is regenerated by the model for the year 2030. Conclusion: The present study recommended that local consistency between models and observations may be a key in knowing the changes in the climatic variability along with its adverse effects on human health, agriculture, ecological sustainability and socioeconomic status in the region.