Newcastle Disease is a frequent disease that occurs every year in Kitutu Chache South Constituency. However, the disease is directly or indirectly linked to changes in climate patterns during the outbreak and spread periods. Therefore, the study sought to examine the influence of climate variability on Free Range Indigenous Chicken (FRIC) death occurrence due to the spread of Newcastle Disease. The study adopted a descriptive research design with a sampling size of 500 farmers. The research used purposive selection to administer a questionnaire to poultry farmers in Kitutu Chache. From 1990 to 2019, climate data were obtained from the Kisii Meteorological Services office. The data were analysed using descriptive statistics in STATA-14, and multiple linear regression models were used to examine the relationship between climate variability and NCD. To determine trends in climatic variability, the climate trend data were analysed in R-Studio using the Mann-Kendall trend test with Sense slope estimators. The results showed that there was a significant increase in minimum and maximum temperatures at (p < 0.05); and a decreasing trend in the mean amount of rainfall, though it was not significant (p > 0.05). Moreover, climate factors were found to strongly influence the spread of Newcastle Disease (p < 0.001) hence FRIC death occurrence; rainfall was found to positively influence the spread of Newcastle Disease, while minimum temperatures were found to be negatively correlated. Therefore, the study concluded that climate factors were influencing the spread of the Newcastle Disease Virus. Finally, the study recommended that the county and the national governments of Kenya harmonise climate issues when drafting policies to curb the spread of Newcastle Disease among FRIC.