August in Grand Teton National Park is a good month: highs around 78°F, lows around 40°F. Crowds: peak crowds — #1 busiest of the park's 12 months. Still peak season; warm days, and afternoon thunderstorms build fast over the peaks. The editorial best window here is July & September. You get about 13h 59m of daylight. To finish Paintbrush Canyon–Cascade Canyon Loop (8h 50m) before dark, leave the trailhead by about 11:33 AM.
Month data reviewed · how we check this
| Verdict | Good A solid visit with a caveat — usually crowds or heat. |
|---|---|
| Temps °F | 78° high / 40° low |
| Crowds | peak crowds · #1 busiest of the park's 12 months |
| What August is like | Still peak season; warm days, and afternoon thunderstorms build fast over the peaks |
| Best window (whole year) | July & 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 78°F. TRAILS WE HAVE NOT MEASURED ARE LEFT OUT RATHER THAN GUESSED
WHAT AUGUST ASKS OF YOU HEREGrand Teton National Park in September — Best window, highs around 68°F, crowds: busy (aspen gold and elk rut, with noticeably thinner crowds than midsummer).
Our verdict for August is "Good". A solid visit with a caveat — usually crowds or heat. Expect highs around 78°F and lows around 40°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 July & 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 68°F and crowds at the "busy" level.
About 13h 59m on August 15: the sun rises around 6:27 AM and sets around 8:26 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.
Paintbrush Canyon–Cascade Canyon Loop takes about 8h 50m of walking, so on August 15 you would need to leave the trailhead by about 11:33 AM to finish before dark — the sun sets around 8:26 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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