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. You get about 14h 02m of daylight. To finish Mount Washburn (2h 45m) before dark, leave the trailhead by about 5:41 PM.
Month data reviewed · how we check this
| 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
DAYLIGHT ON AUGUST 15 · LOCAL PARK TIME (MDT)COMPUTED FROM THE PARK'S OWN COORDINATES FOR THE 15TH — THE MIDDLE OF THE MONTH STANDS FOR IT, AS IT DOES FOR CLIMATE NORMALS. WITHIN A MONTH THESE TIMES SHIFT BY UP TO AN HOUR
LEAVE THE TRAILHEAD BY — TO FINISH BEFORE DARK ON AUGUST 15WALKING TIMES ESTIMATED FROM EACH TRAIL'S MEASURED DISTANCE AND ELEVATION GAIN — A PLANNING FIGURE, NOT A PACE. ADD YOUR OWN MARGIN FOR PHOTOS, REST AND CROWDS. WATER AT THE COOL-WEATHER RATE, BECAUSE THIS MONTH AVERAGES 77°F. TRAILS WE HAVE NOT MEASURED ARE LEFT OUT RATHER THAN GUESSED
WHAT AUGUST ASKS OF YOU HEREYellowstone 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.
About 14h 02m on August 15: the sun rises around 6:25 AM and sets around 8:27 PM local park time (MDT). Computed from the park's own coordinates, so it is the light you actually get at the trailhead, not the nearest city's.
Mount Washburn takes about 2h 45m of walking, so on August 15 you would need to leave the trailhead by about 5:41 PM to finish before dark — the sun sets around 8:27 PM local park time (MDT). Walking times are estimated from each trail's measured distance and elevation gain, so treat them as a planning figure and add your own margin for photos, rest and crowds.
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