August in Arches National Park is a tough month: highs around 97°F, lows around 66°F. Crowds: busy — #5 busiest of the park's 12 months. Monsoon peak — violent storms, flash floods, roads close after rain. The editorial best window here is April–May & September–October. You get about 13h 40m of daylight. To finish Devils Garden Trail (full loop) (2h 45m) before dark, leave the trailhead by about 5:25 PM.
Month data reviewed · how we check this
| Verdict | Tough Closures, harsh weather or very limited access — plan carefully. |
|---|---|
| Temps °F | 97° high / 66° low |
| Crowds | busy · #5 busiest of the park's 12 months |
| What August is like | Monsoon peak — violent storms, flash floods, roads close after rain |
| Best window (whole year) | April–May & September–October |
| Peak crowds (whole year) | Apr–May, Sep–Oct |
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 HOT-WEATHER RATE, BECAUSE THIS MONTH AVERAGES 97°F. TRAILS WE HAVE NOT MEASURED ARE LEFT OUT RATHER THAN GUESSED
WHAT AUGUST ASKS OF YOU HEREArches National Park in September — Best window, highs around 88°F, crowds: peak crowds (the sweet spot returns; labor day weekend is a peak).
Our verdict for August is "Tough". Closures, harsh weather or very limited access — plan carefully. Expect highs around 97°F and lows around 66°F, with crowds at the "busy" 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 April–May & September–October, and the peak-crowd months are Apr–May, Sep–Oct. August itself we rate "Tough".
September we rate "Best window" against "Tough" for August, with highs around 88°F and crowds at the "peak crowds" level.
About 13h 40m on August 15: the sun rises around 6:32 AM and sets around 8:12 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.
Devils Garden Trail (full loop) takes about 2h 45m of walking, so on August 15 you would need to leave the trailhead by about 5:25 PM to finish before dark — the sun sets around 8:12 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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