Calamba's weather is characterized by a warm and humid climate throughout the year, with temperatures consistently above 20°C. The hottest months are April to May, with average highs reaching 31-35°C, while June to August experience slightly lower temperatures due to the onset of the southwest monsoon. The coolest months are January to February, but temperatures still range from 21-34°C. September and October also have moderate temperatures, averaging around 28°C. Overall, Calamba's temperature is relatively stable throughout the year, with minimal seasonal variation.