[5] Average annual precipitation of 15 inches (380 mm) comes in rain and snow.

The summer precipitation accumulation (April through September) averages 10.5 inches (270 mm).

The coldest temperature recorded in the county in recent times was −47 °F (−44 °C) in February 1936, and the warmest was 107 °F (42 °C) in July 2002.

Big Timber receives 286 sunny days on average.

[citation needed] As of the 2010 census, there were 3,651 people, 1,590 households, and 1,045 families in the county.

In terms of ancestry, 25.3% were German, 22.6% were Norwegian, 13.0% were American, 12.8% were Irish, 10.8% were English, and 7.3% were Scottish.

[12] Sweet Grass County is also Republican at a local level.