SteadyTapeQuantitative Market Research

Summer Peak Timing

Median summer peak Aug 3; September is the weakest month. Early peak (pre-mid-July) → Q3 negative 73% of the time (median -5.6%) vs +4.2% for a late peak.

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When does the S&P 500 top out in summer? The high lands ~Aug 3 (median); July is the last strong month, September the weakest of the year. An early peak (before mid-July) preceded a negative Q3 ~3/4 of the time. With midterm / year-ending-6 / Q1-down-Q2-up cohorts and this year’s analogs.

Median summer peak
Aug 3
Weakest month
September
Early-peak Q3
-5.6%
73% negative
Late-peak Q3
+4.2%
25% negative
2026 cohort
midterm, year-ending-6, Q1-down/Q2-up
Sample
99 summers

When to run this study

Run June–September. Frames where the S&P typically makes its summer high (median Aug 3), the September soft patch, and — the key watch — whether the current year makes a fresh high after mid-July (healthy) or has already peaked (early peaks preceded a negative Q3 ~3/4 of the time).

Historical results

Summer peak by cohort

CohortnMedian peakAvg peakClimb to peakPeak→fall lowQ3
All years99Aug 3Jul 2910-7.902.80
Midterm (yr 2)25Aug 11Jul 286-10.502.80
Year ending in 610Aug 6Jul 2511-7.501.30
Q1 down + Q2 up23Jul 27Jul 2912-7.903.10
Midterm + Q1↓Q2↑6Aug 4Aug 410-10.806.30