The US National Hurricane Center (NHC) said the storm crossed the coast on Monday evening.
It had strengthened at sea to a category five storm before making landfall, with maximum sustained winds of up to 160mph (260km/h).
As it struck Nicaragua it weakened to a category four, but the NHC said it remains “extremely dangerous”.
The agency warned of “catastrophic winds, [a] life-threatening storm surge, and torrential rainfall” in its latest update.
“What’s drawing closer is a bomb,” President Juan Orlando Hernández of neighbouring Honduras said at an earlier press conference.
media captionMassive waves crash down on the shores of San Andrés in the Caribbean
Iota is the strongest Atlantic hurricane of the year and only the second November hurricane to reach category five – the last was in 1932.
This year’s Atlantic hurricane season has broken the record for the number of named storms. For only the second time on record officials have had to start using the letters of the Greek alphabet to start storm names.
Honduras, Guatemala and Nicaragua have evacuated residents living in low-lying areas and near rivers in the Atlantic coastal region which Iota is expected to hit.
Before reaching Central America the storm moved past the Colombian island of Providencia in the Caribbean, cutting off electricity.
The country’s President Iván Duque said Providencia could have been hit badly by the storm and stressed there had been “very poor” communication after it struck.
AFP news agency reports that one person was killed on the island.
media caption Heavy rains as Hurricane Iota nears land
The effect of the rains could be particularly devastating in areas already drenched by Hurricane Eta two weeks ago. The NHC says Iota made landfall just 15 miles south of where that storm hit the coast on 3 November.
Eta left at least 200 people dead. The worst-hit area was Guatemala’s central Alta Verapaz region, where mudslides buried dozens of homes in the village of Quejá, with some 100 people feared dead.
At least 50 deaths were reported elsewhere in Guatemala.
Source/BBC
