Overview: TulumTulum (Mexico) in general has a tropical climate. Temperatures during the day are in the range from 29 °C (84 °F) in January to 33 °C (92 °F) in August. Temperatures during the night go from 18 °C (64 °F) in January to 23 °C (73 °F) in June. Sea temperatures are in the following range: 26 °C (79 °F) in February to 29 °C (85 °F) in September. The least rainy month in Tulum is March with its 3 days of rain, the rainiest month is September, when it rains 15 days.