Most of the victims are in El Salvador, where heavy rains led to deaths of 15 people and disappearance of seven others.
It may only be June 3, but Tropical Storm Cristobal has already become the third named storm of the Atlantic hurricane season.
The storm developed in the Bay of Campeche and threatens further life-threatening, dangerous floods across parts of Central America and Mexico before heading towards the Gulf Coast of the United States by the end of the weekend.
Cristobal formed as a result of a large system called a Central American Gyre and the remnants of Tropical storm Amanda, which originally formed in the Eastern Pacific before moving northeastwards and crossing Central America.
At 06:00 GMT on Wednesday, a US Air Force Reserve Hurricane Hunter aircraft located the centre of the storm about 70km (45 miles) from Ciudad del Carmen in southeastern Mexico.
Cristobal will continue to slowly rotate around the Bay of Campeche, crossing the southern coast late on Wednesday before wandering back into the open waters on Thursday night and Friday.
Surface observations have measured winds of about 95km/hour (60 mph) with much higher gusts. The tropical-storm-force winds extend outwards up to 110km (70 miles) from the centre.
Cristobal is expected to produce total accumulations of up to 250 to 500mm (10 to 20 inches) of rain. Additional rainfall still lingers across the Pacific coast over Chiapas, Guatemala and El Salvador.
Life-threatening floods and mudslides are possible across all of these areas before the storm heads towards the southern US.
Heavy rain and high surf are expected along the Gulf Coast early in the weekend. Areas from Texas to Florida have been advised to monitor the progress of Cristobal.