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

Shoulder · VisitWhen score 78/100 · #4 of 12 months

May is a solid shoulder-season month to visit Gateway Arch National Park: crowds run 36% of the July peak (170,789 average visits). Weather: highs average 77°F and lows 57°F, with 4.8″ of precipitation and 14.3 hours of daylight. Computed from NPS and NOAA data.

Crowds in May

Gateway Arch averages 170,789 recreation visits in May — 36% of what July, the peak month, draws. Trailheads and parking fill accordingly.

Weather & daylight

Days are mild (highs average 77°F), and nights stay mild (lows average 57°F). This is one of the wetter months (4.8″ of precipitation on average). Mid-month daylight runs 14.3 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 May.

What to pack for Gateway Arch in May

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

• Rain shell + pack cover — 4.8″ of precipitation is normal this month
• Waterproof boots — plus navigation and a basic first-aid kit — 4.8″ of rain is normal this month

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

Also at their best in May

Other parks whose computed May verdict is a best window — same NPS × NOAA formula:

• Lake Clark in May — 7% of peak crowds, highs 59°F, score 96/100
• North Cascades in May — 11% of peak crowds, highs 69°F, score 96/100
• Katmai in May — 1% of peak crowds, highs 52°F, score 95/100
• Gates of the Arctic in May — 12% of peak crowds, highs 56°F, score 94/100

Common questions

See also: the best national parks to visit in May · Last verified 2026-09-24