Yellowstone weather in September
“Mild and bright — an underrated time to visit.”
Roughly 9 rainy days across the month, on average.
In september, Yellowstone settles into its quieter, cooler pace. The city keeps a different pulse than in summer or midwinter, and travellers who arrive with the right expectations are rewarded.
Days average around 16°C (61°F), cooling to 5°C after sunset. Rainfall is moderate — around 9 rainy days spread through the month. Long days of sunshine reward early starts.
These figures are climatological averages, drawn from a decade of daily records via the Open-Meteo Archive — not a forecast. But they are honest, and they are the sort of thing a good travel guide ought to tell you before you book the flight.
What to pack for Yellowstone in September
- •A light layer for cool mornings and evenings
- •A merino base layer for the cold evenings
- •Comfortable, broken-in walking shoes
- •A small daypack that won't look like a tourist beacon
What to pack for Yellowstone in September
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Where to stay in Yellowstone
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Compare hotels on Booking.com→September vs. the rest of the year
How this month compares in Yellowstone. Tap any month to read more.
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Best time to visit Yellowstone
September is one of the best months to visit Yellowstone — alongside June, July, August. Ten-year climate data confirms it: comfortable temperatures, manageable rainfall, and a healthy dose of sunshine.
See the full best-time-to-visit guide for YellowstoneOther places with a similar climate right now
Yellowstone in September — FAQ
Q01Is September a good time to visit Yellowstone?
Is September a good time to visit Yellowstone?
Yes — it is a good time to visit, with pleasant, comfortable weather. In September, Yellowstone averages a high of 16°C (61°F) and a low of 5°C (41°F), with 59mm of rainfall across roughly 9 rainy days.
Q02What is the average temperature in Yellowstone in September?
What is the average temperature in Yellowstone in September?
The average high temperature in Yellowstone during September is 16°C (61°F), with an average low of 5°C (41°F). These figures are averaged from ten years of daily records (2015–2024, Open-Meteo Archive).
Q03How many rainy days does Yellowstone have in September?
How many rainy days does Yellowstone have in September?
Yellowstone averages approximately 9 rainy days in September, with a total monthly rainfall of about 59mm. This is based on daily precipitation records where days with 1mm or more of rain are counted as rainy days.
Q04What should I pack for Yellowstone in September?
What should I pack for Yellowstone in September?
For Yellowstone in September, pack layered clothing for changing temperatures, a merino base layer for evenings, comfortable walking shoes. These recommendations are based on the ten-year weather averages for this specific month.
Q05How crowded is Yellowstone in September?
How crowded is Yellowstone in September?
Tourist crowds in Yellowstone during September are typically moderate — shoulder season, a sweet spot between crowds and weather. Consider this when planning accommodation — prices track crowd levels closely.