Matt

what was the humidity level?  Drier than San Francisco I expect.

what was the elevation above sea level?  a little higher I expect.

That should answer some of the distance gain.  I will be interested in any temperature responses.  

As an example, we have a new bunker at our course which, when it first opened in summer (dry around 15% humidity and warm) was reachable.  Now in winter (humidity around 65% and cool) the bunker seems a good 15 yards further away .  I expect my 'strength' off the tee will return in the summer.

James B

The heat of the ball is a factor a warmer ball goes further than a cold one.
The heat of the air is another factor.
The figures I've heard mentioned are for every 2 deg celsius a driver carries 1 yard further. A tee shot that carries 260 yards at 20C only goes 250 at 0C.

According to a USGA rep, the ball goes one foot further for every degree over 70F, or about three yards further at 80 degrees, six yards further at 90 degrees, etc.  Of course, the same is true going below 70F.  At 50 degrees, you can expect to lose 20 feet, or about 7 yards.

First of all I hope you got a cart in that kind of heat.
Twas 102 here recently and I quit after 13 holes due to heat exhaustion.

Anyways, to the question.
My ball, in the heat, went 10-15 yards further with my drives and I figured maybe a half club farther with my irons.
I hit my driver, with roll, about 280.  If you shot 69 I suspect you hit something around that far.  I simply add 10-15 yards to my drives, which doesnt atter unless you are trying to clear something or stay short of something.  Otherwise, bomb away.  How far do you hit your driver and other clubs.  The longer you hit, the more extra distance you get.
I personally think the thing that matters more is the half club more on your approach.  That is going to come in more than a little extra driver distance.

A golf ball travels further in humid air because humid air is less dense than dry air.

That's correct, even though it seems counterintuitive.

The effect of heat is much greater than that of humidity -- the ball does go a tiny bit further in humid air, but it is only maybe a yard's difference between a 'very dry' and 'very humid' day in any particular locale.


http://wahiduddin.net/calc/calc_da.htm

Here's a neat little web site you can plug the numbers in to compare "relative density".  Consider 100% to be normalized sea level density -- plug in 16 feet altitude, 57 degrees, 30" barometric pressure and 57 degree dewpoint and you get 100% relative density or normalized sea level.  Those are conditions on a cool clammy day at Pebble Beach, for example.

If you plug in 1/2 mile elevation (2640 feet) 95 degrees, the same 30" pressure and 60 degree dewpoint, for Sand Hills on a typical summer day, you get 84.54%, meaning the air is about 15% less dense there.  That doesn't mean you'll carry the ball 15% further, since drag isn't linear to air density, but it helps you see the magnitude of the difference between various conditions.

High ball hitters get more help/hurt from air density since drag is a bigger factor the longer the ball is in the air.  The less dense the air is, the less effect wind has on the ball, and the harder it is to get the ball up in the air via backspin (so you might want a higher lofted driver in Denver than in Palm Springs)  However, the ball will lose less spin during its flight so it will bite a bit better in less dense air.

Altitude and temperature dominate, and air pressure makes more difference than you'd think, but even Tiger isn't precise enough to tell any difference humidity can possibly make.