I was in a flight recently (march 22nd) from SBCF to SBGR (Brazil). It's usually a 1h10m flight, but mine took roughly 20 minutes more. I saw the flight path in FlightAware and there's an unexpected (to me) detour mid-flight:
I looked for other instances of this scheduled flight and there are more extreme cases, such as this one:
In this case, the actual flight distance was 833km whereas the straight-line distance is measly 496km.
Obviously it would be difficult to pinpoint the exact reason why this happened, but what factors could lead to taking such a different than expected route?