How Weather Affects Baseball Games

Baseball's Outdoor Variable

Unlike basketball or hockey, most baseball is played outdoors. The ball travels through actual atmosphere, affected by temperature, humidity, wind, and altitude. A fly ball that's a home run in one condition is a routine out in another.

We track weather for every outdoor MLB game. It's not just a curiosity—it's a factor that meaningfully shifts expected run scoring and pitcher performance.

Wind: The Biggest Variable

Blowing Out

Wind blowing toward the outfield helps balls carry. At Wrigley Field, the most famous example, a 15 mph wind blowing out can add 20-30 feet to fly balls. Warning track flies become home runs. Deep drives become souvenirs.

Games with strong outward wind see higher scoring, more home runs, and advantage to power-hitting teams. Pitchers with high fly ball rates struggle more.

Blowing In

Reverse the wind and you reverse the effect. Wind blowing in from the outfield knocks balls down. Hitters have to absolutely crush it to get one out. This helps ground ball pitchers and hurts fly ball offenses.

Crosswinds

Crosswinds create asymmetry—one field plays deeper than the other. Left-handed hitters might have advantage or disadvantage depending on direction. We check not just wind speed but wind direction relative to the field orientation.

Temperature Matters

Hot air is less dense than cold air. Baseballs travel farther in warm weather. The difference is measurable: a ball that travels 400 feet at 60°F will go about 5 feet farther at 90°F. Over a full season, that's dozens of extra home runs on balls hit to the warning track.

Early April games in cold Midwest cities play very differently from August games in the same parks. Don't compare offense directly across temperatures.

Humidity and Altitude

Humid Air

Contrary to intuition, humid air is actually less dense than dry air (water molecules are lighter than nitrogen and oxygen). Balls carry slightly farther in humid conditions. The effect is smaller than wind or temperature but measurable.

Altitude

Coors Field in Denver, at 5,280 feet elevation, is famous for a reason. The thin air means balls carry farther and breaking pitches break less. A curveball that drops 6 inches at sea level only drops 5 inches in Denver.

We bake altitude into our venue factors. Coors isn't weather—it's constant—but it's the most extreme example of atmosphere affecting play.

Which Games to Watch

Day games in summer show the biggest temperature effects. Evening games cool off as they progress—what was a hitter's park in the first inning plays more neutral by the seventh.

Wrigley Field wind days are legendary. Check our wind factor before any Cubs game.

Oracle Parkin San Francisco often has marine layer and wind blowing in from the bay. It's one of the toughest parks for hitters.

Fenway Park's jet stream can push balls toward or away from the Monster. Wind patterns there require local knowledge.

How We Use Weather Data

For every outdoor game, we pull forecast data for game time. We look at:

• Temperature at first pitch
• Wind speed and direction
• Precipitation probability (affects whether game happens as scheduled)
• Humidity levels

We combine this with park factors and starting pitcher profiles. A ground ball pitcher in windy conditions has less variance than a fly ball pitcher. Weather cuts both ways depending on style of play.