Keystone (SD) Weather & Climate: Best Time to Visit

Average temperatures, rainfall, sunshine and the best time to visit Keystone.

Climate overview of Keystone

Keystone, South Dakota, United States of America, sees big temperature differences between seasons, with July peaking at 28°C (82°F) and February dropping to 3°C (37°F).

Keystone sees a moderate amount of rain/snowfall, totalling around 536 mm (21 in) per year. It experiences a distinct dry season from November to March, creating some seasonal variation.

Keystone Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Keystone — and find the best time to visit.

Monthly Temperature in Keystone

Visitors to Keystone can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a comfortable 28°C (82°F) in July, the warmest time of the year, to a chilly 3°C (37°F) during cooler months like February.

At night, you can expect temperatures ranging from 14°C (57°F) in July to around -10°C (14°F) during February.

Check out our detailed temperature page for more information.

Temperature ranges by month

Rainfall in Keystone

Generally, Keystone experiences moderate precipitation patterns, averaging 536 mm (21 in) yearly. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, May it receives high rainfall, averaging 114 mm (4.5 in) of precipitation, recorded across 15 rainy days. In contrast, the driest month January brings less snowfall, with 8.4 mm (0.3 in) over 6 snowy days. For more details, please visit our Keystone Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

Best Time to Visit Keystone

During June, July, August and September, Keystone experiences its most favorable weather, with temperatures between 23°C (73°F) and 28°C (82°F). These mild conditions make it an excellent time for a visit.

The weather does bring rainfall during this period, between 35 mm (1.4 in) and 81 mm (3.2 in).

Need help choosing your next travel destination? We offer a specialized tool that matches you with locations based on your weather preferences. Explore destinations that suit your climate preferences.

Frequently asked questions about the climate in Keystone

What is the best time to visit Keystone?

June, July, August and September typically offer the most optimal weather in Keystone. In contrast, January, February and December tend to have less optimal conditions. Keystone has a distinct dry season from November to March.

What temperatures can I expect in Keystone?

Daytime highs range from 3°C (37°F) in February to 28°C (82°F) in July. Nighttime lows range from -10°C (14°F) to 14°C (57°F). Temperatures vary considerably through the year.

How much rain does Keystone get?

Annual rainfall is around 536 mm (21 in). May is the wettest month with 114 mm (4.5 in), while January is the driest with 8.4 mm (0.3 in).

Keystone 3-Day Forecast

Keystone (SD) 3-Day Forecast

Keystone on the map

Keystone is highlighted — select any city to see its climate.

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Where to go in July — average daytime high across popular destinations.

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