Dow Jones Industrial Average in September: seasonality and history
Since 1897, the Dow has risen in September in 42% of years (54 of 129), with an average return of −1.18% and a median of −0.56%. That makes September its #12 month of 12.
Average−1.18%
Years up42%
Best year1939 · +13.49%
Worst year1931 · −30.70%
The seasonal path through September
Cumulative sum of each day's average return through September, all years since 1897.
| Strongest days | Avg | Up |
|---|---|---|
| Sep 2 | +0.27% | 59% |
| Sep 5 | +0.25% | 57% |
| Sep 16 | +0.23% | 62% |
| Weakest days | Avg | Up |
|---|---|---|
| Sep 26 | −0.25% | 44% |
| Sep 10 | −0.19% | 47% |
| Sep 20 | −0.19% | 45% |
Seasonal trend windows touching September
- ▼ Bearish Sep 7 – Sep 30 · 24 days · seasonal Σ −1.93%
September in recent years
| Year | Dow in September |
|---|---|
| 2026 | −4.29% |
| 2025 | +1.87% |
| 2024 | +1.85% |
| 2023 | −3.50% |
| 2022 | −8.84% |
| 2021 | −4.29% |
| 2020 | −2.28% |
| 2019 | +1.95% |
| 2018 | +1.90% |
| 2017 | +2.08% |
Questions
Is September a bad month for the Dow?
On average, yes: −1.18% since 1897, rising in 42% of years. But the range is wide, from −30.70% in 1931 to +13.49% in 1939, so an average is a tendency, not a forecast.
What are the strongest days in September?
Sep 2 (+0.27%, up 59% of years), Sep 5 (+0.25%, up 57% of years), Sep 16 (+0.23%, up 62% of years).