Danielle's maximum sustained winds increased to near 135 mph (215 kph) with some additional strengthening possible.
Danielle was located early Friday about 545 miles (875 kilometers) southeast of Bermuda and moving north-northwest near 12 mph (19 kph). The hurricane is forecast to pass well east of Bermuda on Saturday night. But large waves and dangerous surf conditions were expected in Bermuda over the next few days, the National Hurricane Center in Miami said.
Swells from Danielle would also begin arriving on the East Coast of the U.S. on Saturday and were likely to cause dangerous rip currents through the weekend.
Also in the Atlantic, Tropical Storm Earl was moving west with maximum sustained winds near 45 mph (75 kph). Forecasters said Earl could become a hurricane by Saturday night.