Called the Mountain Fire, the blaze was spreading rapidly, with towering flames that sent residents fleeing for safety.
The warning comes days before nations are due to gather for crunch climate talks led by the UN.
Cubans are having a bad sense of deja vu after the second major hurricane and islandwide power outage in two weeks.
Wildfires have spread in California, where thousands of residents have been ordered to evacuate as homes burned.
