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Weather on September 17 at Gateway Arch

Gateway Arch National Park

MOMidwest450 ft elevation
Avg High80°F
Avg Low58°F
Warmest202685°F
Coldest199657°F

Based on 54 years of data from St. Louis, MO

Planning Your Visit

September 17th in Gateway Arch National Park (via St. Louis, MO) typically brings warm fall weather, with average highs around 80°F and lows near 58°F. Over 54 years of records, the warmest September 17th was in 2026 (85°F average), while the coldest was 1996 (57°F) — a 28°F range across recorded history. Rain or other precipitation has occurred on about 26% of September 17th dates historically, with the wettest September 17th recording 1.66" of rain. The last decade has been 9.0°F warmer on this date compared to 20-30 years ago.

The last decade has been 9.0°F warmer on this date compared to 20-30 years ago.

Planning for September 17th in Gateway Arch? Stay hydrated and seek shade during peak afternoon hours.

Year by Year History

YearHighLowPrecipSnow
202698°F71°F0"--
202592°F58°F0"0"
202490°F60°F0"0"
202378°F52°F0"0"
202288°F61°F0"0"
202189°F60°F0"0"
202079°F55°F0"0"
201991°F69°F0"0"
201893°F66°F0"0"
201789°F69°F0.01"0"
201675°F68°F0.94"0"
201585°F68°F0"0"
201466°F53°F0"0"
201374°F60°F0"0"
201273°F64°F0.01"0"
201168°F53°F0"--
201083°F52°F0"0"
200983°F59°F0"0"
200870°F51°F0"0"
200771°F56°F0"0"
200687°F62°F0"0"
200567°F53°F0"0"
200481°F58°F0"0"
200383°F58°F0"0"
200279°F65°F0"0"
200175°F53°F0"0"
200069°F47°F0"0"
199972°F45°F0"0"
199879°F69°F0.43"0"
199792°F69°F0.65"0"
199665°F50°F0.07"0"
199581°F62°F0"0"
199484°F61°F0"0"
199371°F50°F0"0"
199286°F61°F0"0"
199178°F58°F0"0"
199073°F54°F0"0"
198979°F51°F0"0"
198894°F59°F0.3"0"
198783°F58°F1.66"0"
198675°F63°F0.54"0"
198585°F61°F0"0"
198277°F55°F0"0"
198170°F48°F0"0"
198087°F54°F1.6"0"
197979°F42°F0"0"
197883°F67°F1.06"0"
197780°F60°F0"0"
197673°F43°F0"0"
197570°F61°F0.23"0"
197465°F59°F0.07"0"
197380°F58°F0.08"0"
197290°F73°F0"0"
197168°F--0"0"

September 17 at Nearby Parks

Holiday Weather at Gateway Arch

Official NPS WebsiteVisit nps.gov/jeff for park information, alerts, and reservations

Explore More at Gateway Arch

See historical weather for other dates

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