How much does wind affect a pellet?

Far more than most beginners expect. A 10 mph crosswind pushes a typical .22 pellet several inches off course at 50 yards.

Lighter pellets and lower-velocity shots get pushed more. Read wind from flags, grass, leaves, and mirage in the scope. Most airgun shooters prefer to wait for lulls rather than try to hold off in gusty conditions. .22 and .25 pellets are less wind-affected than .177, which is one reason hunters prefer the larger calibers outdoors.