Humans can’t breathe in a vacuum. Neither can a story. It has to take place somewhere. Somewhere usually has form, function, climate and weather. Weather can set the mood. “It was a dark and stormy night”, may be trite and cliched, but it is a perfectly good example of the way to make weather a part of the story. Weather can even be a character. Humans against a fierce storm works quite well as a plot. Go ahead, make the weather your antagonist.
Weather and climate are a team, you can’t have weather without climate. The kind of weather you get depends on the climate. A calm day is a nice day and that can be boring in a story. An imminent tornado or hurricane can boost tension by quite a lot. It can add danger and spice to what otherwise might be a boring day. Suit your weather to the climate. Tropical storms do not happen in temperate climates. A couple on a picnic would be menaced by a thunderstorm, much less either a hurricane or tornado. A good downpour or blizzard can force characters to remain with one another when they would much rather leave and go elsewhere. Just keep in mind a blizzard doesn’t happen in the tropics. Then again, if something magical happens perhaps it screws with the weather.
A walk in a park is nice when the weather is cooperative. A walk in the rain, may or may not be fun for your characters. If rain isn’t in your forecast, try blistering heat or subzero temperatures. Make your characters uncomfortable. The weather can help you do that.
The weather is one of those tools that we often forget to put into our stories. It can influence the mood of the scene. The moon cast shadows over the courtyard, gives the reader a sense of what time it is – night. Have a wild wind rip through your scene to halt the action while everyone runs after articles of clothing or paper plates. As I said before, the weather can up the ante on a conflict. It can complement the conflict in a scene. It can also contrast it. A heated argument during a raging thunderstorm has a different feel than one taking place on a calm sunny day or one in a car during a blizzard.
You can also have your characters on the high seas during a hurricane, struggling to survive. Whatever your story, add in a little weather to mix and see what happens. You might find your characters in dire straits or heading for a picnic. Whatever happens, you need to ground your stories with a little weather to bring it into the realm of believability.
That is the ultimate goal of a story – believability. Your reader has to be able to suspend disbelief for that to happen. Characters interacting with weather can help you achieve that important goal. So throw a snowball at your character. Drench her with a sudden shower. Make a character chase a hat or vital piece of paper. Your readers will thank you for it.