Although the Shelter Cluster is reporting that 99.6 percent of those in need have received some sort of shelter, a report from CNN shows just how inadequate that shelter is. CNN reports on the situation on the ground after a downpour Monday night:
At the central plaza in Port-au-Prince, now home to thousands of displaced Haitians, water pelted rows of tents, seeping inside from every direction Monday night. At the Champs de Mars people tried to close shut entrances, some with thin cotton sheets or blankets. Mothers rushed to move children sleeping on the ground.

Suddenly, the constant noise of the street came to a halt, replaced by the thud of monstrous drops falling hard from the sky. The only welcomed sight: gleeful children cooling off after another scorching day.

The water quickly started collecting along the roadside. Aid workers say they fear that constant rain will overflow garbage- and rubble-filled canals, flooding the encampments that have sprouted on their banks.

The situation in some camps could be life threatening.
CNN continues:
At another much smaller camp in seaside Carrefour, water gushed down the hill and through the tents.

There are also worries that unsanitary conditions will unleash vicious disease outbreaks – malaria, cholera, dengue fever.
And concludes:
They are homeless in the poorest nation in the Americas. Homeless in a nation that’s highly disaster prone and vulnerable to flash floods because of environmental degradation.

Haitians know what to expect of the rainy season, unlike the earthquake. Except this year, many have no roofs over their heads.