Has your game been off par in recent months? Are your long shots few and far between; is the Tiger missing entirely from your tank, and has your drive lost all the whoosh and zoom it seemed to have last summer? If that describes you to a tee, take heart; it may be that the weather is to blame.
Once hit by the club, the distance travelled by a golf ball is determined by gravity and by the frictional drag of the air through which it flies. Gravity exerts a downward force on the ball as soon as it is launched, providing a constant pull to bring it back to earth; the frictional drag continually slows it down, and makes it hit the ground significantly sooner than if the ball were travelling in a vacuum.
Gravity is constant, but the drag experienced by a golf ball depends, inter alia , on the density of the surrounding air. The denser the air the greater, almost in direct proportion, is the drag.
And the three factors that most influence the density of the air are altitude, humidity and temperature. The elevation of the golf course is the most important. In the mile-high city of Denver in the United States, for example, air density is about 15 per cent less than at sea level. All other things being equal, therefore, one would expect a golf ball to travel about 15 per cent farther in Denver than it might at Ballybunion or at Woodbrook. So for a long drive, shoot from a high tee.
Humidity is a factor because water vapour is less dense than dry air. The more moisture the air contains, therefore, the less dense the combined medium, and the less resistance the ball experiences in its flight. But the effect is relatively small; in fact - again all other things being equal - one could expect to drive a golf ball only a few yards farther on a very humid day than on a very dry one.
And the advantage of humidity disappears completely if the air is so moist as to be saturated and drops of fog or rain occur. The droplets, with their high density, counteract and ultimately reverse the initial gains from high humidity, and reduce the distance travelled by the golf ball.
Temperature, finally, has a significant effect. Warm air expands and becomes less dense than cooler air. On a given golf course, therefore, one might expect to drive a golf ball 10 to 20 yards farther on a hot, humid day in summer than one might on a dry, cold day around this time of year.