September · Alaska
Best time to visit Katmai National Park in September Weather, crowds & prices
Weather in Katmai National Park in September
Average temperature 6°C, 139 mm of rain, about 0 days with 6+ hours of sunshine and 89% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
4.0/10
Ranked #6 of 12 months
- Avg temp
- 6°C
- Rainfall
- 139 mm
- Humidity
- 89%
- Days with 6h+ sun
- 0
- Crowd Density
- Moderate Crowds
- Average Expenses
- $$ · Moderate Cost ($$)
September in Katmai National Park scores 4.0/10 for nature and wildlife travel - an above-average month (#6 of 12). Expect around 6°C, 139 mm of rain, and roughly 0 days with 6+ hours of sunshine this month.
Katmai protects a remote volcanic landscape, salmon rivers, and a major brown-bear population, with Brooks Camp its best-known visitor base.
September in Katmai National Park — off-season conditions
Expect 6°C (42°F) in September. A good month for city streets, viewpoints and long meals; leave swimming for another season.
139 mm of rain signals a properly wet month, with only almost no days with 6+ hours of sunshine to count on — build indoor options into the schedule.
That is 4/10 on the same scale — 6th of 12 months, versus 7.5/10 for the best month here.
Pack a mid-weight jacket, long sleeves and shoes you can walk 15 km in, a proper rain shell rather than an umbrella, footwear you can get muddy.
Budget for mid-season pricing, and crowds are moderate.
If your dates are flexible, June is materially better in Katmai National Park — 3.5 points higher on the same scale.
Frequently asked
- What is the weather like in Katmai National Park in September?
- In September, Katmai National Park averages 6°C, 139 mm of rain, and about 0 days with 6+ hours of sunshine. Its climate-comfort score is 4.0/10.
- Is September a good time to visit Katmai National Park?
- September earns a 4.0/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Katmai National Park in September?
- Expect about 139 mm of rain in September. Average humidity is 89% and there are about 0 days with 6+ hours of sunshine.
Curated in Katmai National Park
Tickets & experiences
Things to do in Katmai National Park
Katmai National Park, Alaska. Live activities and tours from GetYourGuide, matched to this destination.