NFL running back rushing in wind and rain

Across 3,416 qualifying outdoor games by 135 lead backs from 2006 to 2025, bad weather buys volume. In heavy rain the lead back takes +1.26 carries for +9.1 yards against his own season form — both clear significance. In 15–20 mph wind he takes +0.97 carries, but the yardage gain (t = 1.50) does not separate from noise. Yards per carry never moves significantly in any band. Weather changes how often a team runs, not how well.

The top figure in each cell is the raw band average; the smaller figure is the gap against the back's own season baseline, with its t statistic. Anything under roughly 2 is noise and is greyed out. Light rain is a clean null on all three measures — the effect only appears once rainfall is genuinely heavy.

Two disclosures. The 40-game minimum was fixed before any band was inspected and is applied to every study we publish; the gale band holds only 39 qualifying lead-back games and so sits below it — its large-looking +8.0 yard gap is direction only and is not used in any headline or in pricing. The dry-only column also falls below the minimum in the strong and gale bands. And the calm row is negative by construction: a back's baseline contains his own bad-weather games, so the calm and bad-weather rows are mirrors of each other.

Windy and wet is where the volume shift is strongest, and it is also the only cell where yards per carry leans negative. The reading we are comfortable with: the worse the conditions, the more a team leans on the run, without the run itself getting any better per carry.

The per-back view can be distorted by substitution — a lead back who sits down in the fourth quarter of a blowout loses carries the weather did not take. So the same bands are also run on total team rushing, every back's carries summed per team-game and compared to the league average for that same season.

The team view agrees and extends the picture: in 20 mph+ wind teams run +2.17 more times than the season average across 80 team games (t = 2.21), while the yardage gain stays inside noise. This is the only place gale-force wind clears our minimum sample, and even here it is a volume result, not an efficiency one.

Lead-back workload has fallen steadily across the window: qualifying outdoor lead backs averaged 19.2 carries for 80.6 yards in 2006 and 15.7 carries for 68.9 yards in 2025. A study that pooled two decades against a single league average would hand weather the credit for the league's move to committees and passing volume. Because each baseline is built inside a single season for a single back, that drift cannot reach the weather comparison at all.

• Volume rises, efficiency does not. Carries move significantly in heavy rain, strong wind and windy-wet games; yards per carry clears significance nowhere.
• Heavy rain is the only full result. It is the single band where extra carries come with extra yards (+9.1 yards, t = 2.75 across 159 games).
• Light rain does nothing. A drizzle is not a weather game. The shift needs 2.5 mm or more in the game window.
• It fits the passing side. Our quarterback study finds passing efficiency falling in the same conditions. Teams running more when the ball is hard to throw is the same story told from the other side.

• Sample: 3,416 qualifying outdoor lead-back games, 2006–2025. A game qualifies when the back took the most carries for his team, carried at least 8 times, and logged at least 8 such games that season so his baseline is stable. Tied team leads are dropped. Domes and closed roofs are excluded entirely rather than used as a control.
• Weather: hourly reanalysis at the stadium's own coordinates, wind taken at kickoff, rainfall summed across the game window.
• Baseline: leave-one-out mean of the same back's other qualifying games in the same season, computed separately for carries, rushing yards and yards per carry. The team table instead compares each team-game to the league average for that season.
• Not controlled: opponent run defence, game script and score differential, injury substitution, wind direction relative to the field, and play-calling tendency. A team that protects a lead by running in a gale shows up here as extra carries, which is part of the effect we are measuring rather than a separate one.
• No prop or betting lines are attached to these games, so this study reports performance against a back's own form and makes no claim about whether the market prices weather correctly.

Data generated 2026-09-23. Numbers refresh as the archive tops up; corrections are dated and kept visible.

• NFL QB Passing Yards in Wind — the passing-side companion: what wind costs a quarterback.
• NFL Wind & Totals Study — how far wind bands cut the final score.
• NFL Turnovers in Bad Weather — why wet and windy football does not mean extra giveaways.

• Open-Meteo ERA5 historical reanalysis — archive-api.open-meteo.com (hourly game-window weather at each venue’s own coordinates)
• ESPN NFL scores and odds — espn.com/nfl (schedules, final scores and consensus closing totals)
• Internal NFL historical game archive — venue identity, roof status and final scores.
• Internal NFL rushing boxscore archive — per-game rushing lines parsed from public boxscores.
• Every dated change we have made to a published study is listed on our corrections log.