The Mexican government said the country had not seen a similar weather crisis since 1958, when the country was simultaneously hit by two tropical storms, also on separate coasts.
The governor of the Gulf Coast state of Veracruz announced that 12 people died when a landslide smashed into a bus travelling through the town of Altotonga, about 40 miles northwest of the state capital.
More than 23,000 people fled their homes in the state due to heavy rains spawned by Ingrid, and 9,000 went to emergency shelters. At least 20 highways and 12 bridges had been damaged, the state's civil protection authority said.
Some of the heaviest damage was in the southern coastal state of Guerrero, where Mexico's government reported 15 confirmed deaths from Manuel. State officials said people had been killed in landslides, drownings in a swollen river and a truck crash on a rain-slickened mountain highway.
Flooding closed the main highway from Mexico City to Acapulco, and power cuts shut the resort city's main airport, isolating many tourists over a long holiday weekend. Telephone service was cut around the state, though authorities said it was mostly restored by Monday afternoon.
Mexico's federal Civil Protection co-ordinator, Luis Felipe Puente, told reporters late Sunday that stormy weather from one or both of the two systems also caused three deaths in Hidalgo, three in Puebla and one in Oaxaca.
Manuel came ashore as a tropical storm Sunday afternoon near the Pacific port of Manzanillo, but quickly lost strength and was downgraded to a tropical depression late Sunday. It dissipated into an unorganized rain system Monday.
Manuel dumped heavy rains over much of the states of Guerrero, Michoacan, Colima, Jalisco and Nayarit, presenting a dangerous threat in mountains where flash floods and mudslides were possible.
Late Monday, Ingrid had moved inland over northeastern Mexico and was a tropical depression with maximum sustained winds of 30 mph (45 kph). It was centred about 10 miles (15 kilometres) west of the Ciudad Vitoria, capital of Tamaulipas and was moving west at 5 mph (7 kph). Forecasters predicted the storm would dissipate Tuesday.