S&P 500 · Monthly Heatmap — Twelve Months of Seasonality
Monthly seasonality — Which months tend to rise or fall: a year-by-month return heatmap.
Monthly return colours since 2000. November and April carry the highest win rates; September has the longest history of negative months.
What this page answers
Across a 27 year sample, the S&P 500's highest-probability month is November (positive +77% of the time) and the weakest is February (+48%). Seasonality is a statistical lean, not a trading guarantee — any single year can deviate wildly.
Monthly return colours since 2000. November and April carry the highest win rates; September has the longest history of negative months. The data is refreshed by the History of Market pipeline and published as a stable JSON endpoint for research, citation, and AI-agent use.
Latest Snapshot
- Updated
- 2026-07-17
the S&P 500 monthly win rates
| Month | Share of positive months |
|---|---|
| January | +52% |
| February | +48% |
| March | +59% |
| April | +70% |
| May | +74% |
| June | +59% |
| July | +70% |
| August | +62% |
| September | +50% |
| October | +62% |
| November | +77% |
| December | +65% |
Showing the full record (12 rows). Raw series: https://historyofmarket.com/api/sp500/monthly.json
Static Preview
Data & Source
GET /api/sp500/monthly.json — Canonical dataset endpoint.
Yahoo Finance · Macrotrends · Robert Shiller · FRED · S&P Global · Nasdaq · NBER.
FAQ
Which month is historically strongest for the S&P 500?
November, positive in +77% of sampled years; the weakest is February (+48%).
Where does this data come from?
History of Market combines public market and macro datasets including Yahoo Finance, Macrotrends, Robert Shiller, FRED, S&P Global, Nasdaq, and NBER. The exact endpoint for this panel is linked below.
How often is it updated?
Daily-tier datasets refresh after the U.S. market close, with a broader weekly refresh on Sunday. The timestamp shown on this page comes from the JSON payload.
Can I use the data?
Yes, for research and education with attribution to History of Market. Upstream data sources retain their own terms.