Wind speeds of 89 to 102 km per hour are considered strong gale force winds on the Beaufort Wind Scale.

Here's how it breaks down:

* Beaufort Scale: A scale that describes wind strength based on its observed effects.

* Gale Force: Wind speeds between 63 to 117 km/h (39 to 73 mph).

* Strong Gale: Wind speeds between 89 to 102 km/h (55 to 63 mph).

So, wind blowing at 89 to 102 km/h falls within the range of a strong gale force wind.