Honduras recorded three deaths.
In El Salvador, a man was killed during a mudslide, emergency services reported.
Nicaraguan vice-president Rosario Murillo advised people to stay indoors.
"Sometimes we think we can cross a river and the hardest thing to understand is that we must wait. It's better to be late than not to get there at all," he said on state radio.
The storm is expected to move towards US' Florida, which is still recovering from the battering it received from Hurricane Harvey, a month ago.
Images: twitter.com/NOAA