Almost completely dependent upon the flight segment, takeoff, enroute, landing.
Most airports now have installed microburst detection capability.
Well the ones is Dallas should. For those two segments where aircraft are most vulnerable.
Whenever conditions warranted it, I always added 25 knots (5 kts for may wife and 5 kts each for our 4 children) to my approach speed. Kept me from making contact with the approach lights one time.