The wind scale ranges from 1 to 5, with hurricane categories 3 and above considered major hurricanes.
Forecasters said Kiko could get even stronger in the next day or so, but that its intensity was likely to fluctuate after that.
There were no watches or warnings associated with Kiko and no hazards affecting land.
Meanwhile, Lorena was a Category 1 hurricane with maximum sustained winds near 85 mph (137 kph), though it was expected weaken and become a tropical storm on Thursday, the hurricane center said. Forecasters urged people on the Baja California peninsula and in northwestern Mexico to monitor the storm's progress.
Lorena was centered about 210 miles (338 kilometers) west of Cabo San Lucas, Mexico, and traveling northwest at 12 mph (19 kph).
The forecast said rainfall totals could reach 15 inches (38 centimeters) in some places, and flash flooding and mudslides were possible. Ocean swells generated by Lorena could cause life-threatening rip currents in coastal areas.
Tropical storm warnings and watches were in effect for much of Baja California and parts of northwestern Mexico. On the forecast track, the center of Lorena could move over land on Friday.