Depending on your definition of science fiction, the elements might change a bit. I've seen a few lists of sci-fi characteristics that mandate aliens, a future time setting, and special powers. I don't agree with that, because it would eliminate a lot of the literature I consider great, current sci-fi. For example, I think "Jurassic Park" is great science fiction, and it is not set in the future with aliens or special powers. Michael Crichton's book Timeline takes place in medieval times after a group of current scientists travel back in time. I like a more broad definition of sci-fi and its elements.
Science fiction is a genre that often is about science and technology of the future.
"Often" lets authors pen sci-fi novels in present times. Often also doesn't limit them to science AND tech. It could be both or one or the other. One of my favorite science fiction authors is Orson Scott Card. He wrote the Ender's Game series. Read it. He also writes a lot of fantasy. I saw an interview with him one time in which he was asked what the difference between sci-fi and fantasy is. His definition is my favorite to this day. He said that fantasy has trees and magic and scifi has metal and science.
Fahrenheit 451 is most definitely science fiction. It fits with the future society characteristic. It fits with advanced technologies. There are robot "things" everywhere. Walls double as televisions (which is something that Microsoft is working on right now). It even fits with Card's definition. It's not a novel about forests and magical beings. It's a novel about city life and metallic robots and instruments.