1. On August 20, 1889, the state of Washington was admitted to the Union as the 42nd state. It was named after George Washington, the first president of the United States.

2. In 1968, the Seattle Pilots baseball team played its final game at Sick's Stadium on August 20 before moving to Milwaukee and becoming the Brewers. The Pilots were only in Seattle for one season.

3. The Yakima Valley Museum, located in Yakima, Washington, opened on August 20, 1952. The museum features exhibits on the history and culture of the Yakima Valley, including Native American artifacts, pioneer life, and agricultural traditions.

4. On August 20, 1977, Voyager 2 was launched from Cape Canaveral, Florida. The spacecraft, which is still in operation today, has visited Jupiter, Saturn, Uranus, and Neptune, and provided valuable data about these planets and their moons.

5. The Washington State Fair, also known as the Puyallup Fair, usually begins around August 20 and runs through Labor Day weekend. The fair, which takes place in Puyallup, Washington, features rides, food, livestock exhibitions, and musical performances.