Hurricane Nora was the first tropical cyclone to enter the Continental United States from the Pacific Ocean since Hurricane Lester in 1992. Nora was the fourteenth named tropical cyclone and the seventh hurricane of the 1997 Pacific hurricane season. The September storm formed off the Pacific coast of Mexico, and aided by waters warmed by the 1997–98 El Niño event, eventually peaked at Category 4 intensity on the Saffir–Simpson hurricane scale.

The 1997 Pacific hurricane season was a very active hurricane season. With hundreds of deaths and hundreds of millions of dollars in damage, this was one of the deadliest and costliest Pacific hurricane seasons on record. This was due to the exceptionally strong 1997–98 El Niño event. The season officially started on May 15, in the eastern Pacific, and on June 1, in the central Pacific, and lasted until November 30. These dates conventionally delimit the period of each year when almost all tropical cyclones form in the northeastern Pacific Ocean.