@hydn There is no display limit in Windy. If you are talking about forecast, it is avereged wind for some time period, typically 3 hours. If you are looking for wind gusts which can be much stronger, change the overlay in the right menu.
Please keep in mind that forecasting of peek values is very difficult and real maximal wind value of Irma can be much higher than the forecasted one.
...difference between forecasted wind and gust