Bhavnagar is one of the leading onions producing district of Saurashtra region in Gujarat state. Mahuva, Talaja, Ghogha, Jesar, Palitana are the most contributing talukas to onion production of Bhavnagar district. Onions are grown in three distinct seasons in our country (1) Rabi – planted in April–May (2) Kharif – cultivated from October to December (3) Late Kharif – sown from January to March as a result, onion crops become available in the market during each of these periods corresponding to their respective seasons. In this paper the trend of crop production of onion is analysed with the help of total temperatures and area under cultivation using principal components analysis (PCA) and multiple regression analysis.