The Interior Department estimated about 150,000 people were affected by the flooding, either because of damage to homes or crops or to displacement.
Tabasco is a low-lying state and photos showed many homes in such areas flooded up to their roofs. Rains had threatened to overtop a dam in Tabasco over the weekend.
President Andrés Manuel López Obrador said the government was distributing aid and would clean up riverbeds to reduce the risk of floods.
The flooding caused by cold fronts came after rains associated with Tropical Storm Eta left about 20 people dead in the neighboring state of Chiapas. Relatives gathered Monday in the Chiapas mountain community of San Juan Chamula to bury four of the nine victims there.