The weather around OYO 138 The Chilli Salza Patong on Phuket, Thailand is warm all year round. However, the weather is generally most pleasant from late December to March, or even May, when there are clear skies and sunshine. The “hot season” is from April to May, when temperatures reach their highest. The main “rainy season”, or monsoon season, is between May / June and November, or even as late as December over the last decade or so.