The two things that easily vary during each flight on the same aeroplane are weight (payloads, fuel burns etc) and angles of bank. They vary as follows.
Effect of Weight
Given density ratio, coeff Lift and wing area, the following formula represents stall speed at a given angle of bank.
Vs2/Vs1=SQRT(W2/W1)
Vs1 is the stall speed at Gross Weight 1 (W1)
Vs2 is the stall speed at Gross Weight 2 (W2)
Effect of turning (angle of Bank)
Given density ratio, weight, wing area, Coeff lift are the same, the stall speed in a turn is:
Vs(bank angle)=Vslevel*SQRT(1/COS(bank angle))