At Weather Applied Metrics (WAM), we help teams, broadcasters, analysts, and fans understand how weather impacts the games we love. We specialize in turning complex atmospheric dynamics into engaging sport-specific insights. Our work sits at the intersection of meteorology, aerodynamics, applied physics, and sports analytics — enabling players, teams, leagues, sportsbooks, broadcasters, and fans to account for weather as a measurable, modelable variable in performance.

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Weather introduces variability. But variability is not randomness — it’s physics… and it can be measured, modeled, and even predicted. WAM’s mission is to make these effects visible, explainable, and actionable.

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What We Do

Wind, temperature, humidity, and pressure don’t just describe the environment — they alter the trajectory, speed, and spin of the ball as well as the outcome of plays, games, and even seasons. Using sophisticated weather sensors at stadiums and venues, we are able to measure and quantify atmospheric conditions in real time. This data is integrated with a 3D “digital twin” of each venue using Computational Fluid Dynamics (CFD) models to reveal how wind and airflow interacts with the ball — and the game.

Our Expertise:

• High-resolution wind and weather models, tailored to sports performance, broadcast, and analytics
• Custom CFD (Computational Fluid Dynamics) simulations to analyze airflow in and around stadiums and venues
• Real-time ball flight impact metrics for broadcast, live betting, and tactical decision-making
• Predictive modeling tools for pregame strategy, betting markets, and scenario planning
• Historical reconstructions that isolate the impact of weather on performance and outcomes

Our data has been integrated into NFL, MLB, and ATP live broadcasts, and is utilized for advanced team analytics, professional golf coverage, and proprietary sports modeling systems.

Why It Matters

Contrary to common belief, it isn’t possible to accurately gauge the impact of weather by simply checking the local forecast or looking at flags flying near the stadium. Every venue contains a unique, invisible microclimate — shaped by its architecture, surrounding structures, and local terrain — that standard forecasts cannot capture.

From a baseball carried 12 feet farther on a hot, humid afternoon… To a golf shot knocked off line by a shifting crosswind… To swirling stadium winds enhancing the topspin on a late-match serve… Weather introduces variability. But variability is not randomness — it’s physics… and it can be measured, modeled, and even predicted.

Who We Are

WAM was founded by experts in atmospheric science, engineering, and sports analytics, with deep experience in real-time modeling and simulation. Our interdisciplinary approach ensures that our data provides engaging and useful sport-specific insights and storylines — not just abstract forecasts or weather station data.

Our team consists of physicists, engineers, meteorologists, sports scientists, and former professional athletes. Together we aim to measure and understand how weather influences player evaluation, performance, and outcomes.

We collaborate with professional sports teams, leagues, tech partners, networks, and broadcast teams to translate complex environmental interactions into valuable information that can be leveraged — on the field, in the booth, or behind the models.

What’s Next

This blog will serve as a place to share what we’re learning, highlight interesting case studies, and explain the science behind our work. We’ll explore airflow around stadium structures, the interplay of spin and wind, and how even subtle shifts in weather can shape performance in measurable ways.

Whether you’re a data analyst, broadcaster, coach, or simply curious — we invite you to follow along. Because when the wind plays a role, you should be able to #playthewind.

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Weather plays a defining role in shaping the behavior of the air, and by extension, how a ball travels through it. While the physics of drag and spin are universal, the environment in which they act is anything but. This article unpacks how temperature, humidity, pressure, and altitude work individually and together to influence air density and the resulting ball flight in sports.

Atmospheric conditions don’t just shape the field… they shape the physics.

Temperature

One of the most commonly referenced weather-stats we hear, from the great work of Dr. Alan Nathan, is that an increase in 10°F can add approximately 3 feet of distance to a fly ball.

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Higher Temperatures = Lower Air Density

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There is less drag (air resistance) in warmer air, because the air molecules are more spread out; reducing air density and “boosting” ball flight distances. While warmer temperatures don’t make fastballs faster, pitches will better retain their velocity from the initial release, resulting in a higher velocity at the plate when compared to colder conditions (all other things equal). Respected golf instructor Andrew Rice found with TrackMan data that when temperatures rise about 10°F from morning to afternoon (which happens on most days) the ball carries roughly 2 yards farther.

Humidity

While you may often hear wet, humid weather described as “heavy”, counterintuitively, humid air is less dense than dry air. This is because water vapor molecules actually weigh less than the oxygen or nitrogen molecules they replace. The impact, however, is relatively small.

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Higher Humidity = Lower Air Density

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In coastal regions, dense marine layers can further complicate things by layering cool, humid air near the surface and subtly altering both air density and ball behavior in ways that aren’t always intuitive.

Moisture in the Mix

In sports like tennis and baseball, the balls themselves can absorb moisture from humid environments, making them heavier and altering their aerodynamics and their response to impact. This can have a significantly greater impact on ball flight compared to humidity’s influence on air density and drag. In contrast, golf balls are built with impermeable covers, preventing significant moisture absorption and maintaining consistent behavior regardless of humidity.

Recognizing how important this is, Major League Baseball now requires all teams to store baseballs in humidors, ensuring that moisture content, and therefore ball performance, emains consistent across different parks.

Atmospheric Pressure and Altitude

Altitude is one of the most recognized factors in sports performance because of its large impact. The effect comes mainly from the drop in atmospheric pressure that occurs with elevation which lowers air density. Atmospheric pressure itself is shaped by both altitude (the amount of atmosphere above you) and, to a smaller extent, large-scale weather systems. Low-pressure environments reduce air density, while high-pressure systems increase it.

In Denver, at roughly one mile above sea level, air density drops to about 82% of sea-level conditions. According to Titleist, this results in approximately a 6% increase in distance with your driver. At Coors Field, fly balls travel 5–10% farther and pitches show less movement due to Magnus effects, leading to increased home run totals. To try and counteract this effect, Coors Field has some of the furthest fences of any MLB park!

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Higher Altitude = Lower Air Density

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Atmospheric pressure changes independent of altitude are usually gradual and relatively small compared to the dramatic drop caused by increasing elevation. However, shifts between low- and high-pressure zones can still influence weather conditions, with low-pressure systems bringing rising air, clouds, and instability, and high-pressure systems leading to sinking air, clear skies, and more stable conditions.

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Lower Atmospheric Pressure = Lower Air Density

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Sport-Specific (Ball) Considerations

In golf, atmospheric pressure impacts the ball’s flight through changes in air density but does not alter the ball’s internal pressure, since golf balls are solid and sealed.

In other sports like football, however, external atmospheric pressure can affect the internal pressure of the ball itself, which is why the NFL strictly regulates football inflation between 12.5 and 13.5 psi, a standard that became widely known during the “Deflategate” controversy.

In tennis, ball pressure is not actively regulated during matches, meaning that external pressure and altitude can cause noticeable differences in ball behavior. To address this, the International Tennis Federation (ITF) mandates the use of special high-altitude balls at tournaments held above 4,000 feet.

These pressure differences have minimal impact once a ball is in flight, but can significantly affect how the ball compresses and rebounds, influencing bounce, “feel,” and energy transfer when struck or contacting a surface.

How Atmosphere Alters Outcomes

Weather’s influence on air density provides a scientifically grounded explanation for why the same swing, serve, or throw might produce vastly different outcomes in different conditions. These environmental factors don’t just change the feel of the game, they change the physics, and in doing so, influence decisions made by players, coaches, analysts, broadcasters, and even fans.

Key Takeaways:

• Higher temperatures lower air density, allowing balls to travel farther and better retain speed.
• Humidity reduces air density slightly, but can affect ball mass and elasticity depending on the sport.
• Higher altitudes and lower pressures significantly decrease air density, increasing carry distance and reducing movement on pitched or spinning balls.
• Sport-specific equipment can respond differently to changes in atmospheric variables, with many professional sports organizations having introduced regulations to manage.

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Learn more about Weather Applied Metrics.

Analyzing the aerodynamics of sports and ball flight requires a foundational understanding of the physical forces acting on them in real-world environments. This article introduces the foundational science behind how weather affects ball flight through drag, spin, and fluid dynamics—laying the groundwork for a deeper understanding of the atmospheric effects on sports for coaches, athletes, analysts, broadcasters, and fans alike.

Drag, Magnus Effect, Boundary Layers

In basic physics, we learn Newton’s Laws of Motion: for the flight of a ball, there is an initial speed and angle, impacted only by the force of gravity pulling the ball downward forming a perfect parabolic arc. Newtonian mechanics tells us that any ball hit, kicked, or thrown at the same speed and angle should land in the same spot…

However, in the real world, atmospheric elements introduce aerodynamic forces like drag and the Magnus effect that significantly alter that parabolic trajectory.

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At the core of ball flight physics are two key aerodynamic forces: drag and the Magnus effect.

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These real-world effects, first studied by 19th-century scientists like Gustav Magnus, Navier, and Stokes, and later by researchers such as Dr. Alan Nathan and golf physicist Dr. Alastair Cochran, explain why actual ball flight can look so different from theoretical examples.

Understanding Drag

Drag is the aerodynamic force that resists a ball’s motion through the air — commonly known as air resistance. It depends on factors like air density and ball speed, surface texture, and shape. In real-world conditions, smoother and faster-moving balls experience increased drag. Rough features like golf ball dimples intentionally disrupt the boundary layer to reduce drag and help the ball travel farther.

The Magnus Effect and Spin-Induced Movement

The Magnus effect is the aerodynamic force that causes a spinning ball to curve, lift, or dive by creating pressure differences around it. The Magnus force is always perpendicular to the ball’s path and pushes in the direction that the front of the ball is spinning as it moves through the air. 

Another way to conceptualize this is to imagine the ball spinning through the air and shedding air parcels in the direction opposite to the spin — similar to how a balloon zips around the room when released without being tied off. The expelled air acts like thrust in one direction, causing the ball to accelerate in the opposite. A backspinning ball (below), for example, pushes air downward (blue arrow) in its wake, which in turn creates an upward force (red arrow) that helps the ball stay aloft longer.

The Magnus force is what causes the curving motion we see in tennis topspin serves, baseball curveballs, and bending soccer free kicks, as it pushes the ball in the direction of its spin. The strength of the Magnus Effect depends on spin rate, velocity, and again air density; meaning weather conditions can noticeably alter how much a ball dips, bends, or lifts.

Boundary Layers and Seam Effects

Other secondary aerodynamic effects include boundary layer behavior, where a thin layer of air clings to the ball’s surface and is influenced by surface roughness. Seam effects specific to baseball can also occur, where the orientation of the seams creates asymmetric airflow that can add unpredictable movement to a pitch.

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Air isn’t empty — it’s a dense fluid whose properties define how objects travel, spin, and move.

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Air as a Playing Field

Because air is a fluid, its properties — including temperature, humidity, and pressure — directly affect its density and behavior, meaning that even small changes in the environment can alter the forces acting on the ball and ultimately influence how far, how fast, and how much the ball curves through the air.

Understanding Air Density

Air density is the mass of air per unit volume. It’s the composite variable influenced by temperature, humidity, pressure, and altitude. Each of these different atmospheric components contribute more or less to air density, and it’s the summation of these factors that directly impact what we experience. In a nutshell…

• Lower air density reduces both drag and Magnus forces: balls travel farther, better maintain velocity, but curve less due to Magnus effects.
• Higher air density increases both drag and Magnus forces: balls don’t travel as far, slow quicker, and exhibit more movement due to Magnus effects.

The same throw, hit, swing, pitch, or serve can yield radically different outcomes purely based on air density!

Why Weather Is a Player

The forces of drag, spin, and surface interaction shape every ball’s trajectory. While these forces originate in physics, their real-world impact is constantly shaped by the environment. And at the heart of all of it lies air density — the fluid playing field in which games are won and lost!

Key Takeaways:

• Air isn’t empty — it’s a dense fluid whose properties, especially air density, define how balls travel, spin, and move through space.
• Aerodynamic forces like drag and the Magnus effect respond directly to environmental changes, meaning the same action can yield different outcomes depending on weather conditions.

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Learn more about Weather Applied Metrics.