MLB · Wrigley Field
Wrigley Field wind: what blowing out and blowing in are really worth
Everyone checks the Wrigley flags. We matched every outdoor game since 2021 to game-time wind, sorted it against the field's measured direction, and measured what each wind has actually done to scoring.
The short answer
In 475 games at Wrigley Field (2021–2026), wind blowing out averaged 11.5 runs a game and wind blowing in averaged 7.2. Against the park's own season average, that is a +4.04-run gap — the largest of any MLB park in our park-by-park study.
Runs: out minus in
+4.04
t = 6.62 · p < 0.001 · d = 0.90
Home runs: out minus in
+2.06
t = 8.69 · p < 0.001
Wind out vs closing total
+1.62
t = 3.02 · directional only
95% CI +2.84 to +5.25 for the runs gap (106 out games, 176 in games).
How to read the wind at Wrigley
- Centre field faces 37° (NE). This is MLB's official field direction, from home plate toward centre.
- Blowing out: wind coming from about S to W (172°–262°). That is the south and southwest, the warm-air side of the city.
- Blowing in: wind coming from about N to E (352°–82°). That is the north and east, off Lake Michigan.
- Across: anything in between. Forecasts give the direction wind comes from, so a "south wind" blows out.
Runs and home runs by wind direction
| Wind | Games | Avg wind | Runs per game | Runs vs season avg | Home runs vs avg | Vs closing total |
|---|---|---|---|---|---|---|
| Out | 106 | 12.9 mph | 11.52 | +2.37 | +1.18 | +1.62 |
| In | 176 | 10.7 mph | 7.20 | -1.68 | -0.88 | -0.32 |
| Cross | 151 | 10.4 mph | 9.11 | +0.21 | +0.03 | +0.66 |
| Calm | 42 | 3.7 mph | 9.45 | +0.28 | +0.65 | +1.36 |
"Vs season avg" compares each game with Wrigley's average for that season, so a high-scoring year doesn't skew the result. Calm is under 5 mph. Against calm games, wind blowing out added +2.09 runs (t = 2.40) and wind blowing in cost -1.96 (t = -2.65). The calm group is only 42 games, so read those two as a rough guide.
By compass direction the wind came from
| Wind from | Games | Avg wind | Runs per game | Runs vs season avg | Home runs vs avg | Vs closing total |
|---|---|---|---|---|---|---|
| From N | 74 | 12.8 mph | 7.35 | -1.61 | -1.01 | +0.02 |
| From NE | 78 | 9.7 mph | 6.95 | -1.81 | -0.83 | -0.61 |
| From E | 73 | 8.5 mph | 8.12 | -0.92 | -0.35 | +0.01 |
| From SE | 53 | 9.7 mph | 9.00 | +0.12 | -0.02 | +0.55 |
| From S | 45 | 12.6 mph | 10.51 | +1.43 | +0.74 | +0.73 |
| From SW | 65 | 12.9 mph | 12.02 | +2.84 | +1.27 | +2.17 |
| From W (directional only) | 33 | 12.7 mph | 10.36 | +1.77 | +0.70 | +1.38 |
| From NW (directional only) | 12 | 12.9 mph | 9.25 | +0.19 | +0.02 | +1.00 |
Games at 5 mph and up, grouped into eight compass points. Southwest wind was the strongest scoring wind; north and northeast wind were the most suppressing. Groups under 40 games are directional only.
Does more wind mean more runs?
| Wind | Games | Avg wind | Runs per game | Runs vs season avg | Home runs vs avg | Vs closing total |
|---|---|---|---|---|---|---|
| Blowing out 5-9 mph (directional only) | 33 | 7.7 mph | 11.18 | +1.87 | +1.05 | +1.82 |
| Blowing out 10-14 mph | 41 | 12.8 mph | 12.51 | +3.36 | +1.46 | +2.54 |
| Blowing out 15+ mph (directional only) | 32 | 18.3 mph | 10.59 | +1.61 | +0.95 | +0.23 |
| Blowing in 5-9 mph | 90 | 7.4 mph | 7.33 | -1.50 | -0.67 | -0.39 |
| Blowing in 10-14 mph | 53 | 11.8 mph | 6.85 | -2.07 | -0.98 | -0.57 |
| Blowing in 15+ mph (directional only) | 33 | 17.8 mph | 7.39 | -1.53 | -1.30 | +0.29 |
Each speed group is small (most under 40 games), so this is directional only. There is no clean "stronger wind, bigger effect" pattern. At 15 mph and up blowing out, scoring was higher than average but lower than at 10–14 mph.
The lake-breeze question: spring vs summer
| Wind and months | Games | Avg wind | Runs per game | Runs vs season avg | Home runs vs avg | Vs closing total |
|---|---|---|---|---|---|---|
| Blowing in Apr–May | 66 | 11.1 mph | 7.14 | -1.87 | -1.12 | -0.09 |
| Blowing in Jun–Sep | 110 | 10.5 mph | 7.24 | -1.56 | -0.74 | -0.46 |
| Blowing out Apr–May (directional only) | 33 | 15.4 mph | 10.45 | +1.25 | +1.03 | +0.35 |
| Blowing out Jun–Sep | 73 | 11.8 mph | 12.00 | +2.87 | +1.24 | +2.19 |
The usual story is that cold lake wind blows in through April and May. In our sample, wind blew in for 39% of April–May games and 36% of June–September games — not much different. When it did blow out, summer games ran +1.62 runs higher than spring games, but that gap is not statistically clear (t = 1.42, p = 0.161; only 33 spring out games).
Does the betting total already account for it?
Out-blowing games at Wrigley finished +1.62 runs above the closing total on average (t = 3.02, 95% CI +0.56 to +2.68), going Over in 57 and Under in 45 (56% Overs, Wilson 95% CI 46–65%). In-blowing games finished -0.32 against the close (t = -1.12), which is no clear gap.
Read this carefully. Wrigley stood out only after we looked at all 30 parks, the Over-rate interval still includes the 52.4% break-even point, and this is not a walk-forward test of bets. It shows the market moves the total on a Wrigley wind day; it does not show a proven edge.
Checking today's wind
For the forecast at first pitch, see the Wrigley Field game-time forecast, or compare every park on where the wind is blowing out today.
Method
- All Wrigley Field regular-season games 2021–2026 with a final score: 475 games.
- Wind is the hourly archive reading for the game window at the ballpark's coordinates, compared with the 37° field direction. Out means within 45° of straight out; in means within 45° of straight in; calm is under 5 mph.
- Runs and home runs are compared with Wrigley's own average for that season. Groups are compared with Welch's t-test; we report p-values, 95% confidence intervals and Cohen's d.
- Any group under 40 games is labelled directional only. Results that show no effect are reported too.
- Closing totals are ESPN consensus lines (475 games have one). We corrected the field direction on 6 October 2026; see the corrections log.
Related research
Where this is applied
These findings feed the game-time read on every MLB venue page, using the same sample-size and significance rules published here.
OverUnderWeather Research Desk
Independent data analysis on public sports and weather records. Studies match historical game outcomes to archived game-window weather, apply pre-set sample and significance rules, and publish null results when that is what the data show. Editorial policy and corrections log.
Cite this research
Free to republish with a visible credit and a link to this page. Ready-made citations below — click to copy.
Frequently asked
How much does wind affect scoring at Wrigley Field?
More than at any other MLB park we measured. Since 2021, games with wind blowing out at 5 mph or more scored +4.04 runs more than games with wind blowing in, against Wrigley's own season average (106 out games vs 176 in games; t = 6.62, p < 0.001, 95% CI +2.84 to +5.25).
Which wind direction blows out at Wrigley Field?
Centre field at Wrigley faces about 37° (NE). Wind coming from roughly S to W — south and southwest — blows out. Wind from N to E — north to east, off Lake Michigan — blows in.
Does the wind at Wrigley change by time of season?
Less than the "April lake breeze" story suggests. Wind blew in for 39% of April–May games and 36% of June–September games. Out-blowing games did score more in summer, but that split is too small to call real.
Does the betting total already price wind at Wrigley?
Not fully in this sample: out-blowing games finished +1.62 runs above the closing total (t = 3.02). Wrigley was singled out after looking at 30 parks, so treat it as directional. It is not a proven betting edge.