Keystone (SD) Temperature by Month
Keystone, South Dakota, United States of America has an average annual maximum temperature of 14°C (57°F), ranging from 3°C (37°F) in February to 28°C (82°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.
Keystone Monthly Temperatures
The weather in Keystone experiences significant differences between warm and cold seasons, with big shifts in temperature. At night, minimum temperatures range from 14°C (57°F) in July to -10°C (14°F) in February.
The chart below illustrates the average maximum day and minimum night temperatures in Keystone by month:
From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak.
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 14°C (57°F). To put that in context, here's how it compares to a few well-known destinations:
Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.
Glasgow, Scotland averages 13°C (55°F) a year — mild but often grey, with cold winters and rarely hot summers.
Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters — and seasons reversed compared to Europe.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
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.
