Gateway Arch in August: Crowds, Weather & What to Pack

Shoulder · VisitWhen score 69/100 · #9 of 12 months

August is a solid shoulder-season month to visit Gateway Arch National Park: crowds run 46% of the July peak (217,260 average visits), days average 88°F with 13.7 hours of daylight. Computed from NPS and NOAA data.

Crowds in August

Gateway Arch averages 217,260 recreation visits in August — 46% of what July, the peak month, draws. Trailheads and parking fill accordingly.

Weather & daylight

Days run warm (highs average 88°F), and nights stay mild (lows average 66°F). Average precipitation is 3.7″ for the month. Mid-month daylight runs 13.7 hours.

NOAA 1991–2020 monthly normals, station CAHOKIA ST LOUIS AP, IL US (4 mi from park coordinates, 413 ft elevation) — conditions vary inside the park, especially with elevation. Daylight computed for the 15th of August.

What to pack for Gateway Arch in August

Computed from the month's weather normals above — not a generic list.

• Sun protection and 2L+ water per person — highs average 88°F
• Rain shell + pack cover — 3.7″ of precipitation is normal this month
• Sturdy broken-in footwear, navigation and a basic first-aid kit — every park, every month

If your dates are flexible, consider shifting: The computed best months for Gateway Arch are April and September.

Common questions

See also: the best national parks to visit in August · Last verified 2026-07-16