Thursday was the second major rain in the last week, increasing fears that the 1.2 million displaced from the earthquake will not have adequate shelter before the rainy season begins.

The rains, which only lasted for a few hours, caused some camps to turn into mud, and even flooded parts of Cite Soleil, AP reports. Pictures of the flooding can be seen here, or here.

President Rene Preval told Reuters that:
Every time I meet with foreign leaders and delegations, I tell them that [shelter] is the most urgent need.
The UN, US and EU are all responding, but coordination has been a problem. On February 15 John Holmes, head of relief efforts for the UN, sent an e-mail to his colleagues stating:
…it is also clear that there remain major unmet humanitarian needs, particularly in critical areas such as shelter, other NFIs [non-food items], and sanitation. With the rainy season looming, these unmet needs are taking on additional urgency,
The UN Office of Coordination of Humanitarian Affairs, in their update from February 16, reports that only 24% of shelter needs have been met and that:
The shelter cluster has committed capacity for universal coverage with plastic sheeting by May.
The most recent report, just released, states that:

…the rate of distributions of plastic sheeting has been steadily increasing

However, in the three days between reports the number of tents distributed has remained the same at “over 17,000”, while the number of tarps distributed has only increased from “over 87,000” to “over 93,000.”

The UN is aiming to distribute two tarps to each family, however USAID is basing their projections on just one tarp:
At current distribution rates, the Shelter Cluster expects to achieve universal coverage of at least one plastic sheet per beneficiary household by April 1, prior to the expected onset of the rainy season.
It is imperative that adequate shelter be distributed as soon as possible. With the rains already beginning, having "universal coverage" by April or May will still leave hundreds of thousands of Haitians exposed in the meantime. With sanitation lacking, experts fear an imminent humanitarian emergency.

Edmond Mulet, head of the UN mission in Haiti, addressing a meeting of development ministers in the EU said:
We need latrines, we need field tents, we need plastic sheets so that people can cover themselves.
Mulet added:
The rains are coming, I don't think we are going to be able to shelter all these people in time.
The result, as the AP describes it, is:
…people are planning to stay in some very dangerous places: at the bottom of hillsides they know will collapse in a heavy rain or near riverbeds that are bound to flood. They are crowded into polluted areas where sanitation is limited and disease is already starting to spread.