Aid workers rushed to prepare for a hurricane that forecasters said could hit Haiti this week.
It is a formidable challenge in a nation already coping with a cholera epidemic and trying to help hundreds of thousands still living in tent camps nearly 10 months after a devastating earthquake.
Many people in the camps said they did not know Tropical Storm Tomas might be coming, but there was little they could do living in flimsy shelters to protect themselves from the elements.
"I didn't know about (the storm). Maybe somebody came by to say something yesterday when I was out," said Florence Ramond, a 22-year-old mother and food vendor who is living on the Petionville Club golf course in a refugee camp managed by actor Sean Penn's relief organisation.
Even knowing, Ms Ramond said, she could do nothing to secure her home, a shack made of tarp, wood and a tin door.
The roof blew off in an unnamed September 24 storm that ripped through the capital, killing at least five people and destroying or damaging thousands of tents.
"They always go around and tell us to tie the tarps up, but I don't have a rope," she said.
The family lost their home in the earthquake, which killed Ms Ramond's niece.
Her brother, Joel, is in hospital with cholera in the Artibonite Valley - part of an epidemic that has killed more than 300 people and put more than 4,700 in medical care.
Her infant son, Lovenson, has had bouts of diarrhoea recently that she said are caused by mud flowing into their shelter.
His first birthday was on Monday, which was also the first day of Haiti's Voodoo festival of the dead, Fet Gede. Ms Ramond said she doesn't have money to celebrate either.
Those with more money have a better chance of being prepared. Leonide Paul said she had received news about the storm via an automated text message, and would go out and buy food, water and extra fuel to prepare.
Tomas would be the first major storm to strike Haiti since the January 12 earthquake killed as many as 300,000 people and forced millions from their homes.
It would also be the first tropical storm or hurricane to hit since 2008, when the storms Fay, Gustav, Hanna and Ike battered Haiti in the space of a month, killing nearly 800 people and wiping out 15% of the economy.
Piles of rubble and partially collapsed buildings still fill the capital from the quake. Reconstruction is grinding along without promised aid funds.
There are shortages of 150,000 tarps as well as soap, hygiene kits, field tents, radios and oral rehydration salts for treating cholera, UN Humanitarian Coordinator Nigel Fisher said in a statement.
"We need emergency shelter. We need water and sanitation supplies. And we need as much of it as possible in place before Hurricane Tomas hits," Mr Fisher said.Reuse content