This study assessed the impact of climate change and climate variability on food security in Kenya based on a sample size of 270 farmers randomly selected from semi-arid agro-ecological zones in Kenya. Both primary and secondary data were used in the present study. Data analysis was conducted using descriptive statistics and regression models. The results revealed that increase in temperature and reduction in rainfall had significant effect (p<0.01) on food security in Kenya. Increase in the amount of rainfall by 1 mm in the semi-arid areas enhanced food security by 0.01 kg while increase in maximum temperatures by 1°C reduced food security among households by 0.03 kg. Further, food security of Kenya is affected by increase in temperature and decline in rainfall. One unit increase in temperature would cause USD 3.9 million worth of value to become at risk as compared to USD 118,942 worth when rainfall decreased by 1 mm. Overall, the value at risk in the Kenyan economy is USD 112,351,112.46.