43inches, you obviously don't fly a 737!
3-4 times a year we get a 'lightning strike', at night in bad weather... then do a non precision approach, have a missed approach, lose an engine, do an engine out ILS, go around, catch fire, do an engine out night visual circuit on fire and land.
Whether the flight is all in the clear, or all in the gloop, we reference the instruments the
exact same amount. I imagine that since an airliner instrument scan is
totally independant from the weather (except for the two extremes of low visibility operations, or visual approaches), some pilots treat IF time arbitarily.