Olympic in September: Crowds, Weather & What to Pack
Shoulder · VisitWhen score 59/100 · #7 of 12 months
September is a solid shoulder-season month to visit Olympic National Park: crowds run 67% of the August peak (420,210 average visits). Weather: highs average 69°F and lows 49°F, with 6.1″ of precipitation and 12.6 hours of daylight. Computed from NPS and NOAA data.
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Bring for Olympic in September
- Rain shell + pack coverSee it on AmazonWhy: 6.1″ of precipitation is normal this month.
- Waterproof bootsSee it on AmazonWhy: 6.1″ of precipitation is normal this month.
- Water bottles for the daySee it on AmazonWhy: hydration is one of the NPS Ten Essentials.
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Olympic in September: what the park service says
September follows Olympic's most popular months, July and August. The park says snow can appear in the high country as early as late September, temperatures start to drop and rain increases, and some campgrounds and roads begin closing for winter. Fog can linger on the coast even on sunny days. Call the weather hotline at 360-565-3131 before heading out.
Source: NPS, checked 2026-11-05.
Crowds in September
Olympic averages 420,210 recreation visits in September — 67% of what August, the peak month, draws. Trailheads and parking fill accordingly.
Weather & daylight
Days are mild (highs average 69°F), and nights stay mild (lows average 49°F). This is one of the wetter months (6.1″ of precipitation on average). Mid-month daylight runs 12.6 hours.
NOAA 1991–2020 monthly normals, station QUINAULT 4 NE, WA US (13 mi from park coordinates, 286 ft elevation) — conditions vary inside the park, especially with elevation. Daylight computed for the 15th of September.
What to pack for Olympic in September
Computed from the month's weather normals above — not a generic list.
- Rain shell + pack cover — 6.1″ of precipitation is normal this month
- Waterproof boots — plus navigation and a basic first-aid kit — 6.1″ of precipitation is normal this month
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If your dates are flexible, consider shifting: The computed best months for Olympic are April and May.
Also at their best in September
Other parks whose computed September verdict is a best window — same NPS × NOAA formula:
- Wrangell–St. Elias in September — 25% of peak crowds, highs 56°F, score 84/100
- Guadalupe Mountains in September — 35% of peak crowds, highs 80°F, score 81/100
- Gateway Arch in September — 29% of peak crowds, highs 81°F, score 80/100
- Isle Royale in September — 39% of peak crowds, highs 65°F, score 79/100
Common questions
Is Olympic crowded in September?
Moderately: September runs 67% of the August peak, averaging 420,210 visits (NPS, 2021–2025). See every month at Olympic.
What is the weather like in Olympic in September?
Average highs of 69°F, lows of 49°F, 6.1″ of precipitation (NOAA 1991–2020 normals, QUINAULT 4 NE, WA US station). Compare it with other national parks in September.
What should I pack for Olympic in September?
Rain shell + pack cover; Waterproof boots — plus navigation and a basic first-aid kit — the full weather-computed list is on this page. Going in October instead? Olympic in October has its own list.
See also: the best national parks to visit in September · Last verified 2026-09-24