The region of Satara district experiences summer from March to May, with maximum temperature ranging from 35°C to 43°C and the warmest month is May (43°C) whereas, the monsoon lasts from June to September with moderate to high precipitation during which temperature ranges from 28°C to 32°C along with 80% to 90% relative humidity. The present study was designed to evaluate the effect of THI on the HSP70 gene expression pattern during summer and rainy seasons in Deccani sheep at LFC, KNP College of Veterinary Science, Shirwal, Dist. Satara (Maharashtra). The meteorological variables like temperature and relative humidity were recorded for calculating THI and whole blood samples (06 ml each) of eight non-pregnant, non-lactating and apparently healthy Deccani sheep were collected for HSP70 gene expression pattern during peak summer (month of May) and peak rainy (month of August) seasons in the year 2019. The significantly (P less than 0.01) higher THI was recorded during summer than rainy season. The relative mRNA expression of the HSP70 gene during the peak summer season was found 1.79 folds more as compared to peak rainy season during the present study.