Portugal's Azores archipelago braced on Sunday for Hurricane Gordon which had intensified to Category 2 and was likely to hit the eastern-most islands early on Monday, the civil protection service said.
The Atlantic islands, about 1,000 miles west of the Portuguese coast, are a popular tourism destination and are particularly busy at this time of year.
It said the hurricane was expected to weaken to Category 1 before it passes "very close" to Santa Maria - the most easterly island, where the meteorological service forecast winds with an average speed of 81 mph (130 km/h) and gusts of up to 100 mph (160 km/h) early on Monday.
Category 1 hurricanes have enough strength to uproot trees, blow off poorly attached roof tiles, cause coastal flooding and power outages.
Sao Miguel island, where the region's largest city - Ponta Delgada - has about 44,000 residents, was likely to have winds of about 55 mph (90 km/h). Both eastern islands will also see heavy rainfall and waves of up to 52 feet (16 metres), it said.
The civil protection service recommended reinforcing roofing, doors and windows, and told people not to leave home during the storm. The service was on red alert in the two eastern islands and on medium alert in the central archipelago.