Essential Knowledge For Competitive Players: How Weather Affects The Golf Ball
During the colder months, or simply on days when you have to bundle up, you may notice the golf ball flies shorter. Some may ask if it’s a lack of swing speed due to less frequent play, or the extra layers restricting mobility. While those are contributing factors, the difference also lies in the ball flight dynamics. Today I will dive into the effects of air temperature, altitude, humidity and daytime changes on a golf course.
Cold Air vs Hot Air
Cold air molecules are denser than those of warm air. When the ball flies through cold air, there is greater resistance that drags the ball down. Also, cold temperatures harden the surface of a golf ball making it harder to compress. This requires a player to have more force to reach the same level of compression as a warm day. Therefore, the ball will fly shorter when it is cold outside. However, the most important question from a performance standpoint is how much? A simple formula would be to add or subtract 2 yards of carry for every 10 degrees of distance above or below 70F.
For example, clubs will go about 4 yards shorter on a 50-degree day than a 70-degree day. On a hot day the air is less dense and the ball is easier to compress. When it's 90 degrees the opposite is true: a shot will go about 4 yards further for the same reasons. However, it is not always uniform when it comes to adjustments through the bag, + or - 4 yards is a good rule of thumb on most approaches, but your longer clubs and woods will lose/gain even more distance. So on a 50-degree calm day a hole can easily play a full club longer.
Some players combat this by changing to a lighter driver shaft in the winter that allows them to counteract the loss of distance. Changing the style of golf ball for different weather is not recommended as it can throw off a player’s feel.
Altitude
Altitude can have an even greater effect on the distance. Many competitive players that travel fail to research the altitude of the courses they are competing at. Higher altitudes means thinner air and longer drives. Every thousand foot increase in altitude causes a 1.16% increase in ball flight. To calculate to difference in ball flight you use the formula Altitude/1000 * 1.16 = percent difference. At 5000 ft, this equals a 5.8% increase in distance. That means an entire 10 yards difference at 170 yards. So always check the altitude before you play and compare it to your home course. Playing near the beach will be at sea level, but some courses in North America are at close to 10,000 ft.
Humid vs Dry Air
Humid air ball flight dynamics may be one of the biggest misconceptions in golf. One may assume that humid air may slow that golf ball down since the moisture in the air can give the perception that it's “heavy”. Especially if it's a hot day it can even feel heavier breathing. Believe it or not, humid air is actually less dense and the ball will fly further on a humid day. The reason being water vapor weighs less than oxygen and nitrogen. However, it really doesn’t have a huge effect on the flight and total distance. Drastic humidity changes (90% difference) would only change the distance of a tee shot by about a yard.
Players often incorrectly blame humid air for effects caused by other factors. When it is humid, the ground tends to collect dew or be wet. These will slow the golf ball down more than any change in humidity, especially wet rough.
Morning vs Afternoon Course Set Up
The way a golf course plays changes throughout the day even without the influence of any of the factors described above. Since a golf course is outdoors and a part of nature, there are simple but important differences between morning and afternoon rounds. Morning rounds often have dew, wet rough, but smoother putting surfaces. Throughout the day, a golf course can dry out and increase in firmness (especially on a windy day). Also, the greens, which are meticulously cared for and mowed to short lengths, will grow. Therefore, they become slower in the afternoon. Some species like Poa annua, grow less evenly and could even start to sprout mini buds on the greens by the time the evening rolls around.
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