NOAA seem hell bent on dropping the knot as a basic measure despite
its ideal meter. So here goes with the conversion tables once more:
Saffir-Simpson Scale
Category One Hurricane: 64-82 knots,
74-95 mph,or 119-153 km/hr.
Category Two Hurricane: 83-95 knots;
96-110 mph, or 154-177 km/hr.
Category Three Hurricane: 96-113 knots;
111-130 mph, or 178-209 km/hr.
Category Four Hurricane: 114-135 knots;
131-155 mph, or 210-249 km/hr.
Category Five Hurricane:
Winds greater than 135 knots;
155 mph, or 249 km/hr.
http://www.nhc.noaa.gov/aboutsshs.shtml
THE BEAUFORT WIND SCALE
Force miles/hour knots description
0 0-1 0-1 Calm Sea like a mirror