Temperature, altitude and wind: how many clubs?
- Full-swing yardage
"It's cold, take one more club." "We're up in the mountains, the ball flies." Both are true — but when temperature, altitude and wind are all acting at once, no amount of feel will tell you what the total comes to in clubs.
The Carry Range Finder recalculates the carry of all 14 clubs for the day's conditions. Here is how to use it, and what came out of actually running the numbers.
The picture above is a 7-iron (128 m baseline) on a winter morning: 5 °C with a 3 m/s headwind. The dotted line is the baseline, the solid line today's flight. Into the wind the ball climbs higher, then falls away sharply and lands at 120 m — 8 m short, exactly one club.
Three steps
1. Enter your baseline carries (once)
Enter each club's carry in calm air, flat ground, 15 °C, at sea level. Everything rests on this.
The important part is to leave the roll out. If "150 yards with a 7-iron" is your number including run, your actual carry is shorter. Enter more than you really carry and every adjustment comes out inflated too.
Set a club to 0 and it disappears from the table. Your entries are saved in the browser,
so from next time you only need to change the conditions.
2. Describe today's air
Temperature, altitude, pressure and humidity. For pressure, use the figure from the forecast (sea-level corrected) as it is. If you don't know it, leaving it at 1013 is fine — the effect is small.
3. Wind and elevation
Wind direction is given relative to your target line, as the direction the wind is blowing
towards. For elevation, + is uphill and − is downhill.
Only one column really matters
You don't need to remember how many metres the adjusted carry came to. Just read the "plays like" column and change clubs accordingly.
Here is the whole bag under the same winter-morning conditions:
The "In one line" box at the top tells you how much shorter the ball flies on average — 5.9% here. On the 7-iron row the adjusted carry is 120 m and it "plays like" an 8-iron. Today, take one more club — you can see it at a glance.
Taking a 7-iron with a 128 m baseline under other conditions:
| Conditions | Adjusted | Plays like |
|---|---|---|
| Winter morning (5 °C, 3 m/s into the wind) | 120 m | 8I |
| Mountain course (2000 m altitude) | 137 m | 6I |
| 10 m uphill | 115 m | 8I |
What the numbers showed
Altitude matters far more than temperature
Changes from a 200 m driver, 128 m 7-iron and 96 m pitching wedge.
| Conditions | Driver | 7I | PW |
|---|---|---|---|
| 5 °C | −2 m | −2 m | −1 m |
| 35 °C | +5 m | +3 m | +2 m |
| 1000 m altitude | +7 m | +5 m | +3 m |
| 2000 m altitude | +13 m | +9 m | +5 m |
| 5 m/s headwind | −15 m | −11 m | −9 m |
| 5 m/s tailwind | +12 m | +7 m | +5 m |
Forgetting 1000 m of altitude costs you more than twice as much as being 10 °C out on temperature. And wind beats both. Wind first, then altitude, then temperature is enough.
Elevation hurts short clubs most in relative terms
Playing 10 m uphill:
| Club | Change | Share of baseline |
|---|---|---|
| Driver | −16 m | −8% |
| 7I | −13 m | −10% |
| PW | −14 m | −15% |
In metres, the driver loses the most — its shallower descent angle means it gives up more horizontal distance before reaching the target height. But club selection works in percentages, so the wedge is what feels badly off. This is why uphill short irons and wedges are so often left short.
Humidity barely does anything
Going from 50% to 90% humidity moves every club by less than a metre. "It's humid today, the ball won't go" is a common feeling, but the air density says the opposite: water vapour is lighter than dry air, so a humid day flies very slightly further.
Think of the humidity field as being there to confirm you can ignore it.
A headwind hurts more than a tailwind helps
The same 3 m/s of wind does not act the same way against you and behind you.
| Club | 3 m/s headwind | 3 m/s tailwind |
|---|---|---|
| Driver | −8.6 m | +7.4 m |
| 7I | −6.1 m | +4.5 m |
| PW | −4.8 m | +3.4 m |
The headwind does 1.2 to 1.4 times as much. Drag grows with the square of the ball's speed through the air, so a headwind adds proportionally more drag than a tailwind takes away. A headwind also adds lift, which is why the ball balloons and then stalls on the way down, as in the picture at the top. Think "one club into the wind, half a club downwind" — that asymmetry matches what you see.
You can almost ignore air pressure
Even at 990 hPa with a typhoon approaching, a 7-iron gains only 1.0 m. Under a 1030 hPa high it loses 0.7 m. Forecast pressure is no reason to change clubs. Altitude is another matter: 1000 m up is the same as pressure falling by about 110 hPa, which does matter.
Worked examples
Some common situations, for a player with a 200 m driver, 128 m 7-iron and 96 m pitching wedge:
| Situation | Driver | 7I | PW |
|---|---|---|---|
| Summer mountain course (1000 m, 25 °C) | +9 m | +6 m | +4 m |
| Winter seaside (5 °C, 5 m/s headwind) | −18 m | −13 m | −10 m |
| 15 m downhill | +18 m | +15 m | +15 m |
| 5 m uphill | −7 m | −6 m | −6 m |
On a summer mountain course temperature and altitude both make the ball fly. A 7-iron gains 6 m, close to half a club. Winter by the sea is the opposite: cold air and a strong headwind together cost a 7-iron 13 m, more than a club. Elevation hits the short clubs hardest in percentage terms. On a par 3 that plays 15 m downhill the pitching wedge flies 15 m further, so a distance you would normally hit with a PW only needs a gap wedge.
If a club can't get there, it says so
On a steep uphill shot, a wedge physically cannot climb to the target height. Those clubs get an "out of reach" badge and are dropped from the average. Sometimes you find that a hole you were planning to attack with a wedge simply doesn't reach.
Compare the ball flights
"Show trajectory" on any row draws the baseline flight and today's flight on top of each other. The same club coming in high and long at altitude, or dropping out of the sky into a headwind, behaves completely differently on the green — which the numbers alone don't show you.
Assumptions and limits
- It calculates carry only. Roll is not included.
- Wind is treated as uniform over the whole course; wind shear with height is not modelled.
- Launch angle and spin rate per club use typical values. If your ball flight is unusually high or low, the size of the adjustments will shift somewhat.
Underneath, the tool works out the air density from your conditions and numerically integrates the equations of motion including drag and Magnus lift. For each club it solves backwards for the ball speed that produces exactly your entered carry under baseline conditions, then flies that same ball speed through today's air — the difference is the adjustment.
Rules of thumb for the course
- Get your baseline carries right first. Leave out the roll, and don't trust the range's yardage boards as they are (range balls often fly shorter)
- Worry about wind, then elevation, then altitude, then temperature. Humidity and pressure can be ignored
- A headwind hurts more than a tailwind helps. For the same wind speed, count the headwind as 1.2 to 1.4 times as strong
- Uphill and downhill par 3s hit the short clubs hardest in percentage terms. 10 m uphill is 15% for a pitching wedge
- Read only the "plays like" column. It tells you which club to take
Start by entering your own baseline carries.