How Weather Affects Over/Under Betting: NFL and MLB Totals Guide

Weather is one of the most underrated factors in over/under betting. Wind, rain, cold, and humidity can shift game totals by 5-10 points in football or 1-2 runs in baseball—often before casual bettors even check the forecast.

This guide explains exactly how weather impacts totals in NFL and MLB games, which conditions favor overs vs unders, and how to incorporate weather into your betting process. You'll also learn where to find reliable forecasts and how to avoid the most common weather-related mistakes.

Last updated: January 2025

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Why Weather Matters for Over/Under Betting

Weather affects scoring in outdoor sports by changing how the ball moves, how players perform, and how teams adjust their strategies.

Which Sports Are Most Weather-Dependent?

Highly weather-dependent:

• NFL (outdoor games): Wind, rain, cold, and snow dramatically affect passing and kicking
• MLB: Wind, temperature, and humidity change how far balls carry
• College football (outdoor): Same as NFL

Minimal weather impact:

• NBA: Indoor sport (no weather)
• NHL: Indoor sport (no weather)
• NFL/NCAAF dome games: Controlled environment

Key takeaway: Always check weather for outdoor NFL and MLB games before betting totals. Indoor sports don't require weather analysis.

How Weather Changes Scoring

NFL:

• Wind disrupts passing accuracy and field goal range
• Rain makes the ball slippery, reducing offensive efficiency
• Cold numbs hands and affects ball handling
• Snow slows players down and limits passing

MLB:

• Wind blowing out helps home runs carry farther (favors overs)
• Wind blowing in knocks down fly balls (favors unders)
• Temperature affects ball carry (hot = farther, cold = shorter)
• Humidity can make balls heavier (less carry)

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How Weather Affects NFL Totals

In the NFL, weather can shift a total from 47.5 to 42.5 in a matter of hours.

Wind: The Biggest Factor

Wind is the single most important weather variable for NFL totals.

How wind impacts the game:

• Disrupts passing accuracy (QBs struggle with deep balls and timing routes)
• Limits field goal range (kickers miss more often or teams go for it on 4th down)
• Forces teams to run more, which slows the game down

Wind thresholds:

• 0-10 mph: Minimal impact
• 10-15 mph: Slight impact (watch for gusts)
• 15-20 mph: Significant impact (expect 2-4 points lower total)
• 20+ mph: Major impact (expect 4-6 points lower total, strong under lean)

Example:

• Bills at Patriots, outdoor stadium
• Forecast: 22 mph sustained wind
• Opening total: 47.5
• Adjusted expectation: 43.5 or lower (under likely has value)

Rain: Moderate Impact

Rain makes the ball slippery and fields muddy.

How rain impacts the game:

• Reduces passing efficiency (receivers slip, QBs can't grip the ball as well)
• Increases fumbles
• Teams run more, slowing the pace
• Heavy rain = stronger under lean; light rain = minimal impact

Rain thresholds:

• Light rain (< 0.1 inch/hour): Minimal impact
• Moderate rain (0.1-0.3 inch/hour): Slight under lean (-1 to -2 points)
• Heavy rain (> 0.3 inch/hour): Strong under lean (-3 to -5 points)

Example:

• Packers at Bears, outdoor stadium
• Forecast: Heavy rain throughout game
• Opening total: 45.5
• Adjusted expectation: 42.5 or lower (under)

Cold: Mild to Moderate Impact

Cold weather numbs hands and affects ball handling.

How cold impacts the game:

• Ball becomes harder (less grip, more fumbles)
• Players' hands get cold (drops increase, passing efficiency decreases)
• Teams may run more to control the clock

Cold thresholds:

• 40-50°F: No impact
• 30-40°F: Slight under lean (-1 to -2 points)
• Below 30°F: Moderate under lean (-2 to -3 points)
• Below 20°F (extreme cold): Strong under lean (-3 to -5 points)

Caveat: Some cold-weather teams (Bills, Packers, Bears) are less affected. Factor in team familiarity with cold.

Example:

• Dolphins at Bills, December outdoor game
• Forecast: 18°F
• Dolphins struggle in extreme cold (warm-weather team)
• Opening total: 48.5
• Adjusted expectation: 44.5 or lower (under)

Snow: Strong Impact

Snow slows players down and limits passing.

How snow impacts the game:

• Visibility drops (QBs can't see downfield)
• Field becomes slippery (receivers can't cut as sharply)
• Ball is harder to throw and catch
• Teams run more, slowing the game

Snow thresholds:

• Light flurries: Minimal impact
• Steady snow (accumulating): Strong under lean (-4 to -6 points)
• Blizzard conditions: Extreme under lean (-6 to -10 points)

Example:

• Browns at Bills, blizzard forecast
• Opening total: 46.5
• Forecast: 6+ inches of snow during game
• Adjusted expectation: 38.5 or lower (strong under)

Dome vs Outdoor: Baseline Difference

Dome games average 2-3 points higher than outdoor games.

Why:

• No wind, rain, or cold to disrupt offense
• Perfect conditions for passing
• Faster pace (no weather delays)

Examples of dome stadiums:

• Mercedes-Benz Stadium (Atlanta)
• Caesars Superdome (New Orleans)
• U.S. Bank Stadium (Minnesota)
• Ford Field (Detroit)

Totals adjustment:

• Outdoor game in mild weather: 47.5
• Same matchup in a dome: 49.5-50.5

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How Weather Affects MLB Totals

In MLB, weather affects how far balls carry and how pitchers perform.

Wind: Direction Matters Most

Wind is the biggest weather factor in baseball totals.

Wind blowing out (toward outfield):

• Fly balls carry farther
• More home runs
• Favors overs

Wind blowing in (toward infield):

• Fly balls die at the warning track
• Fewer home runs
• Favors unders

Wind thresholds:

• 0-10 mph: Minimal impact
• 10-15 mph out: Slight over lean (+0.5 to +1 run)
• 15-20 mph out: Strong over lean (+1 to +2 runs)
• 10-15 mph in: Slight under lean (-0.5 to -1 run)
• 15-20 mph in: Strong under lean (-1 to -1.5 runs)

Example:

• Cubs vs Cardinals at Wrigley Field
• Forecast: 18 mph wind blowing straight out
• Opening total: 8.5 runs
• Adjusted expectation: 9.5-10.5 (over)

Temperature: Hot = More Home Runs

Hot weather helps balls carry farther.

How temperature impacts the game:

• Hot (85°F+): Ball travels 1-2% farther per 10°F increase
• Cold (below 60°F): Ball doesn't carry as well

Temperature thresholds:

• Below 60°F: Slight under lean
• 60-80°F: Neutral
• Above 85°F: Slight over lean
• Above 95°F: Moderate over lean (+0.5 to +1 run)

Example:

• Rangers vs Astros at Globe Life Field (retractable roof open)
• Forecast: 98°F
• Opening total: 9.5
• Adjusted expectation: 10.5 (over)

Humidity: Heavy Air Suppresses Offense

High humidity makes the air denser, which reduces ball carry.

How humidity impacts the game:

• Low humidity (< 50%): Ball carries farther
• High humidity (> 70%): Ball carries less far

Humidity thresholds:

• Below 50%: Slight over lean
• Above 70%: Slight under lean (-0.5 runs)

Note: Humidity matters less than wind and temperature but can be a tiebreaker.

Park Factors and Altitude

Certain stadiums naturally inflate or suppress totals.

Hitter-friendly parks (inflate totals):

• Coors Field (Colorado): Altitude (5,280 feet) makes balls carry 10-15% farther
• Great American Ball Park (Cincinnati): Small dimensions
• Camden Yards (Baltimore): Short right field porch

Pitcher-friendly parks (suppress totals):

• Oracle Park (San Francisco): Wind blowing in from left field, cold weather
• T-Mobile Park (Seattle): Large outfield, marine layer
• Marlins Park (Miami): Large outfield, deep fences

Example:

• Rockies vs Dodgers at Coors Field
• Altitude + warm weather + wind blowing out
• Opening total: 11.5
• Even at 11.5, the over might have value due to extreme park factors

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Real Examples: Weather-Adjusted Totals

Example 1: NFL Wind Game

Matchup: Chiefs at Bills, December outdoor game Forecast: 25 mph sustained wind, gusts to 35 mph Opening total: 48.5 Closing total: 43.5 (dropped 5 points)

What happened:

• Public bet the under once weather news spread
• Sharp bettors hit the under early when the total was still 47.5-48.5
• Actual result: 20-17 (37 points, under cashes easily)

Lesson: Check weather early. If you bet under at 48.5, you beat the close by 5 points.

Example 2: MLB Wind Game

Matchup: Cubs vs Reds at Wrigley Field Forecast: 20 mph wind blowing straight out to center field Opening total: 8.5 runs Closing total: 10.5 (moved up 2 runs)

What happened:

• Sharp bettors hit the over early when the total was 8.5
• Public followed, pushing the total to 10.5
• Actual result: 12-9 (21 runs, over cashes)

Lesson: Wind blowing out at Wrigley is a major over factor. Bet early before the line adjusts.

Example 3: NFL Rain Game

Matchup: Seahawks at 49ers, outdoor stadium Forecast: Moderate rain (0.2 inches/hour) throughout game Opening total: 46.5 Closing total: 44.5

What happened:

• Rain reduced passing efficiency
• Both teams ran more, slowing the pace
• Actual result: 21-20 (41 points, under cashes)

Lesson: Moderate to heavy rain favors unders. Adjust your projection by 2-3 points.

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How to Check Weather for Totals Betting

Best Weather Sources for NFL

1. Weather.com (or Weather.gov for NOAA forecasts)

• Check hourly forecast for game time
• Look for wind speed, precipitation, and temperature

2. NFLWeather.com

• NFL-specific weather tool
• Shows game-time conditions and historical weather trends

3. Twitter/X

• Follow beat reporters for real-time updates
• Check team accounts for weather-related news

Best Weather Sources for MLB

1. Weather.com

• Check hourly forecast for first pitch
• Look for wind direction (in vs out) and speed

2. BaseballWeather.com (if available)

• Baseball-specific weather forecasts

3. Park-specific resources

• Wrigley Field is notorious for wind; check local Chicago weather

When to Check Weather

NFL:

• 72 hours before game: Initial check
• 24 hours before game: Refine your projection
• 2-3 hours before kickoff: Final check (conditions can change)

MLB:

• 6-12 hours before first pitch: Most MLB weather is stable
• 1-2 hours before first pitch: Final check for wind direction

Live betting:

• Check weather during the game (conditions can shift mid-game in MLB)

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Common Weather Betting Mistakes

Mistake 1: Ignoring Weather Entirely

The error: Betting NFL totals without checking wind or rain forecasts.

The fix: Always check weather for outdoor games. Set a reminder to verify conditions 24 hours and 2 hours before game time.

Mistake 2: Overreacting to Light Rain or Mild Wind

The error: Betting under because there's a 20% chance of light rain or 8 mph wind.

The fix: Only adjust for significant weather:

• Wind over 15 mph
• Moderate to heavy rain
• Extreme cold (below 25°F)

Mistake 3: Betting Too Early Without Weather Updates

The error: Betting Sunday night for a Thursday night game, then the forecast changes to 25 mph wind.

The fix: Check weather 24-48 hours before game time. If the forecast changes significantly, adjust or don't bet.

Mistake 4: Ignoring Dome vs Outdoor Split

The error: Treating all games the same, regardless of venue.

The fix: Factor in 2-3 points higher for dome games on average.

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Summary

Weather is one of the most powerful—and underused—factors in over/under betting.

NFL weather checklist:

• Wind over 15 mph: Strong under lean
• Moderate to heavy rain: Under lean
• Cold below 25°F: Moderate under lean
• Snow: Strong under lean
• Dome games: 2-3 points higher than outdoor games

MLB weather checklist:

• Wind blowing out 15+ mph: Strong over lean
• Wind blowing in 15+ mph: Strong under lean
• Temperature above 90°F: Slight over lean
• High humidity: Slight under lean
• Park factors (Coors Field, Oracle Park, etc.): Major impact

Where to check weather:

• Weather.com / NFLWeather.com for NFL
• Weather.com / BaseballWeather.com for MLB
• Check 24 hours and 2 hours before game time

Next steps:

• Use the Over/Under Calculator to adjust your projections based on weather
• Read the Over Under Betting Strategy Guide for more advanced tactics
• Check Common Over/Under Mistakes to avoid weather-related errors

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