One in every 45 Yemenis will have contracted the disease by December as "a direct consequence of a conflict that has devastated civilian infrastructure and brought the whole health system to its knees," the ICRC said in a statement.
More than 370,000 people have fallen ill and 1,800 have died since late April in Yemen's second cholera outbreak in less than a year, according to the ICRC and the World Health Organization, AFP reported.
A war between the Saudi-backed government and Houthi movement has killed thousands of people and displaced millions.
A string of vital ports along the country's Red Sea coastline are blockaded, leaving millions of people with limited access to food and medicine.
Less than half of the country's medical facilities are currently functional.
The war in Yemen, one of the world's most impoverished countries, has killed more than 8,000 people and wounded a further 44,500 since Saudi Arabia and its allies joined the conflict in 2015.