Seattle
- Microsoft went public on March 13 at $21 a share; Bill Gates became a billionaire on paper at age 31.
- C/Z Records' Deep Six compilation introduced Soundgarden, Green River, the Melvins, Malfunkshun, Skin Yard, and the U-Men — the first widely distributed document of what would be called grunge.
- The Goodwill Games were awarded to Seattle for 1990; planning began.
- Mariners outfielder Phil Bradley made the All-Star team; the Seahawks were a perennial AFC contender under Chuck Knox.
The United States
- The Space Shuttle Challenger broke apart 73 seconds after launch on January 28, killing all seven crew members including teacher Christa McAuliffe.
- The Iran–Contra affair was exposed in November, becoming the defining scandal of Reagan's second term.
- The Statue of Liberty centennial was celebrated on July 4 with a televised ceremony in New York Harbor following a major restoration. (Reference, NPS)
- Top Gun, Platoon, Aliens, and Stand by Me were released.
- The Tax Reform Act of 1986 simplified and lowered federal income-tax rates.
The World
- The Chernobyl nuclear-plant accident in Soviet Ukraine on April 26 was the worst civilian nuclear disaster in history; its scale was concealed for days. (Reference, World Nuclear Association)
- Halley's Comet returned to the inner solar system for the first time since 1910. (Reference, NASA)
- Diego Maradona's "Hand of God" goal and his "Goal of the Century" minutes later eliminated England at the World Cup in Mexico; Argentina won the tournament. (Reference, FIFA)
- Ferdinand Marcos was overthrown in the Philippines' People Power Revolution; Corazon Aquino became president.
