Short answer: 25 mph is the practical limit for most golfers. The round is playable but difficult — expect 5–8 extra strokes, 3+ clubs of adjustment, and balls oscillating or moving on exposed greens. If you're playing for fun, go; if you're playing for score, reschedule.
If wind moves your ball at rest on the green after you've marked and replaced it, you replace it; if you haven't marked it yet, you play it from the new spot. Knowing this before a 25 mph round saves arguments.
Low-handicap players who flight the ball well can survive; most golfers should treat the round as practice in trajectory control. Our playability score rates sustained 25 mph wind firmly in the "Poor" tier on most days.