Keystone (CO) Temperature by Month
Keystone in Colorado, United States of America sees significant seasonal temperature differences, with daytime highs between -2°C (28°F) in January and 22°C (72°F) in July, averaging 9°C (48°F) annually. Explore the full monthly breakdown below.
Keystone Monthly Temperatures
Depending on the time of the year, temperatures range from pleasant to very cold in Keystone. Nighttime lows follow the same pattern, ranging from 6°C (43°F) to -14°C (7°F).
The chart below illustrates the average maximum day and minimum night temperatures in Keystone by month:
The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM.
The chart below shows the average temperature throughout the year:
Temperature: Keystone vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
very warm
warm
pleasant
moderate
cold
very cold
Keystone vs World: Temperature Compared
Keystone's average annual maximum temperature is 9°C (48°F). To put that in context, here's how it compares to a few well-known destinations:
Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.
Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.
San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation — summers are often cool and foggy, winters mild.
Melbourne, Australia averages 20°C (68°F) annually — known for unpredictable weather, with four seasons sometimes happening in one day.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained — so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.
For more on Keystone's weather — including monthly rainfall, sunshine hours, and humidity — visit our Keystone climate page.
