Basin is a town in, and the county seat of, Big Horn County, Wyoming, United States. The population was 1,285 at the 2010 census. The community is located near the center of the Bighorn Basin with the Big Horn River east of the town. Basin's post office, built in 1919, is listed on the National Register of Historic Places.
Basin is located at 44°22′44″N 108°2′35″W (44.378777, -108.043100).
According to the United States Census Bureau, the town has a total area of 2.43 square miles (6.29 km2), of which, 2.40 square miles (6.22 km2) of it is land and 0.03 square miles (0.08 km2) is water.
Basin is known as The Lilac City. Basin hosts the Big Horn County Fair each summer.
Basin has a cold desert climate (Köppen climate classification BWk). The town had the highest temperature ever recorded in Wyoming, 115 °F (46 °C), on August 8, 1983, and also holds the state record high temperatures for April (93 °F or 33.9 °C in 1948) and July (114 °F or 45.6 °C in 1900).
In general, the eastern portion of the Bighorn Basin is hotter than the rest of Wyoming during the summer months. Due to frequent low humidity, daily temperature ranges are large, whilst due to the very dry conditions snowfall is among the lightest in the northern Rockies and Plains region – it is not uncommon for no measurable precipitation to fall in a month between September and April. There are an average of 50.9 days annually with highs of 90 °F (32 °C) or higher and an average of 186.0 nights with lows of 32 °F (0 °C) or lower.