Keystone Weather in September
Keystone in September sees moderate daytime temperatures of 17°C (63°F) and nighttime lows of 2°C (36°F). Moderate rainfall is typical, with around 40 mm (1.6 in) for the month.
Rainfall in Keystone in September
Climate statistics over the past 30 years suggest around 12 days of rain, with 40 mm (1.6 in) average for the month. The rainfall pattern this month is fairly balanced. Showers tend to be moderate rather than extreme.
Temperature in Keystone in September
Expect highs of 17°C (63°F) in Keystone in September, with nights dropping to around 2°C (36°F). A light jacket or extra layer can be useful, especially outside the warmest hours of the day. Nights drop to 2°C (36°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.If your ideal day consists of dry skies and pleasant temperatures, June, July and August typically offer the best circumstances for Keystone.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Keystone's climate page.
Keystone Temperature in September
Min Temperature
2°C (36°F)
Max Temperature
17°C (63°F)
Chance of Rain
40%
Precipitation
40 mm (1.6 in)
Rainy days
12 days
Best Places in the United States of America in September
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Keystone in September
Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Rain gear is recommended, you can expect wet weather on multiple days.What To Do in Keystone in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Keystone's climate page.
See the full Keystone climate overview or explore weather in the United States of America.
