Parnaiba's climate is warm and humid year-round, with temperatures rarely dipping below 20°C. In the summer months of January, February, and March, temperatures consistently range between 30-35°C, making it one of the hottest periods. The cooler months from June to August bring slightly lower highs around 32-33°C, but still quite warm overall. Autumn in September and October brings a slight increase in temperature, with highs reaching up to 38°C, while winter months from November to December are characterized by relatively mild temperatures ranging from 29-34°C. The temperature fluctuations throughout the year are generally moderate, making Parnaiba's climate suitable for tropical vegetation.