August in Yellowstone National Park is a good month: highs around 77°F, lows around 44°F. Crowds: peak crowds — #1 busiest of the park's 12 months. Peak crowds continue; afternoon thunderstorms. The editorial best window here is June & September.
| Verdict | Good A solid visit with a caveat — usually crowds or heat. |
|---|---|
| Temps °F | 77° high / 44° low |
| Crowds | peak crowds · #1 busiest of the park's 12 months |
| What August is like | Peak crowds continue; afternoon thunderstorms |
| Best window (whole year) | June & September |
| Peak crowds (whole year) | Jul–Aug |
CROWDS: RELATIVE SEASONALITY FROM NPS VISITATION STATISTICS · TEMPS: APPROXIMATE NOAA NORMALS AT MAIN VISITOR ELEVATION — HIGH COUNTRY RUNS 10–20°F COLDER
Yellowstone National Park in September — Best window, highs around 66°F, crowds: moderate (elk rut echoes through the valleys; crowds thin, mornings crisp).
Our verdict for August is "Good". A solid visit with a caveat — usually crowds or heat. Expect highs around 77°F and lows around 44°F, with crowds at the "peak crowds" level. Temperatures are approximate NOAA normals at the main visitor elevation; crowd levels follow published NPS visitation statistics.
Across the full 12-month review, the best window is June & September, and the peak-crowd months are Jul–Aug. August itself we rate "Good".
September we rate "Best window" against "Good" for August, with highs around 66°F and crowds at the "moderate" level.
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