Haitians observe a day of mourning Friday to mark one month since the devastating earthquake left much of the capital, Port-au-Prince, and surrounding areas in ruins, and more than 217,000 people dead.
At least 1 million others were left homeless after the 7.0 magnitude quake struck Haiti on January 12.
An international aid operation is in progress in Haiti, which had already been struggling to recover from tropical storms that wiped out 15 percent of the country's economic output in 2008.
Earlier Thursday, heavy rains soaked the Caribbean country, raising fears about flooding and the spread of disease among the people left homeless by the quake.
Reports from Port-au-Prince say the homeless were drenched as few had more than bed sheets strung over poles for shelter.
The United Nations and other aid agencies say the rains are an indication of what can be expected from the rainy season, which begins in just weeks.
They say shelter and sanitation are the two greatest concerns. Aid workers are rushing to try to set up more permanent shelters.
Separately, European Union foreign policy chief Catherine Ashton says the EU will send a military mission to Haiti to help provide shelter for the quake victims before the start of the rainy season.
Ashton said in a statement from Brussels Thursday that shelter is "the most burning need" in Haiti and that its government and the United Nations requested the help. There were no details on the size of the mission.
The nation of 9 million people is the Western Hemisphere's poorest country.
Some information for the report provided by AFP and AP.