Golf weather and wind: how to read a forecast before you play

Four numbers decide how a golf course will play, and the temperature is not one of them. Most golfers open a weather app the morning of a round, look at a symbol and a number of degrees, and close it again — which is roughly as useful as checking the scorecard for the par and nothing else.

Reviewed for golf accuracy by Josh Cassin.

The forecast is one of the few pieces of preparation available to an amateur that costs nothing and is worth real strokes. Reading it properly takes about a minute. Here is what to look at, what the numbers mean once you are standing over the ball, and where the app stops being right — which is earlier than you would like. If you want the wind laid straight over the hole you are playing, that is what the course map does.

The four numbers that matter

Average wind speed. This is the number every app leads with, and it describes the day rather than the shot. Under 15 km/h you can largely ignore the wind on approach shots. Between 15 and 30 it is worth a club on most holes. Above 30 it becomes the main thing the round is about, and scoring expectations move with it.

Gusts. This is the number that decides the disasters, and most golfers never look at it. A forecast of 20 km/h gusting 45 is not a 20 km/h day — it is a day on which one shot in six is hit into 45 km/h of wind, and you do not get to choose which one. On any shot with water or out of bounds behind the green, club for the gust and accept being short.

Direction. A compass bearing is useless information until you lay it over the routing. Two minutes with the course map before you leave tells you which three holes play into it, and those three holes are where your round will be decided. Decide in the car park that the long par 4 into the wind is a three-shot hole today. That decision is impossible to make on the tee, where pride is present.

Precipitation. Light rain costs a little distance and a lot of grip, both manageable. Standing water is a different game: the ball stops where it lands, run-up shots stop existing, and every approach becomes a carry number. The forecast's distinction between 1 mm and 8 mm is the distinction between those two rounds.

How much wind actually changes your club

The rule of thumb worth carrying, for a mid-iron carrying around 150 metres:

Wind	Effect on carry	In practice
15 km/h into	−7 to −8 m	Half a club
25 km/h into	−13 to −15 m	A club and a half
40 km/h into	−25 m and unpredictable	Two clubs, and aim for the fat part
15 km/h behind	+4 m	Barely a change
25 km/h behind	+7 to +8 m	Half a club
25 km/h across	~15 m of drift	A club's worth of aim, not of club

The asymmetry is the important part. A headwind costs roughly twice what the same tailwind gives back. This is not folklore — it follows from what wind does to ball flight. Into the wind, the ball climbs higher, stays up longer, and drops almost vertically with no run. Downwind it flattens, lands shallow and runs, so some of what it gains it gains on the ground rather than in the air. "It hurts more than it helps" is a true statement about physics, and playing as though wind were symmetrical is the most reliable way to be short on every into-the-wind approach for an entire round.

Wind takes a bigger share from short clubs than from long ones. A wedge is in the air a long time relative to how far it goes, and it spins hard, which is exactly what a headwind exploits. A 100-metre wedge into 25 km/h can play 115. A driver into the same wind loses proportionally less. Most amateurs do the opposite — they take an extra club with the driver and none with the wedge.

Reading wind on the course, against what the app says

The forecast describes the air above the course. You are playing on the ground, and the two disagree constantly.

Trees and terrain change everything below the treeline. A hole cut through woodland can be dead calm at ball level while the tops are bending, and the ball will find the wind again the moment it climbs above the shelter. This is why a shot that felt right lands twenty metres short with no obvious explanation.

Elevation changes the wind you get. An elevated tee is in more wind than the fairway below it, so the shot starts in one wind and finishes in another. On courses with real relief — and French golf has more of it than its reputation suggests — this is a per-hole variable rather than a per-round one.

The flag on the green is the best instrument on the course, because it reports the wind at the place your ball is going rather than the place you are standing. Read it before you choose a club, not after.

The honest summary: the forecast is for planning, the flag is for clubbing. Use the app to decide how the round should be played and what to pack. Use your eyes to decide what to hit. An app that claims to tell you the wind at your ball, right now, on this hole, is claiming a resolution that no weather model has.

What a forecast will not tell you

It will not tell you the wind will swirl in the bowl around the twelfth green, because no model has a resolution of thirty metres. It will not tell you the greens are running slow because they were hollow-tined on Tuesday. And it will not tell you whether the course is playable, because that is a decision the club makes with information the model does not have.

Which leaves the forecast doing exactly one job well: telling you, before you leave, what kind of round to expect and what kind of round to plan. That is worth a minute. It is not worth a subscription. If you want to go further into how much of your scoring is decided before you swing, the statistics hub is the place that argument continues, and what counts as a good score puts a windy day in context.