Help interpreting a wind rose diagram
No, you've misunderstood it. There's lots of information you're missing. Every data point is information, and you've listed a tiny proportion of them.

Furthermore, 4-7 km/h and 11-16 km/h aren't frequencies at all, they're wind speeds. The distance from the centre gives you the frequency.

So the spike towards N means that North winds are much much more frequent than the NNW and NNE winds. There may be some protection in those directions such that the winds that would come from there, are actually getting channelled to come from the North instead. Or there's a particular time-of-day effect, or a recording artifact, or one of a dozen other explanations that only someone with more information about the site and the data collection could assess.

However, the fastest winds don't blow from that direction at all: they're all coming from the quadrant between S and W.