If you are going to write a believable story, the climate and weather will come into it. Often, you can have the weather cause problems for your characters. I have a main character in a work that I’m currently revising who is a cat. She won’t like rain or snow, but will like nice sunny weather. I can make it rain or snow on her when she needs to go somewhere. It won’t necessarily deter her from doing what she needs to do, but it will make it more difficult for her. Weather can make things happen. Let’s face it. The Wizard of Oz wouldn’t work without the tornado.
That’s what the weather can do for your story. The climate will come into it by determining what kind of weather you can use. The climate of Kansas allows for tornadoes. They are not infrequent there so it works for The Wizard of Oz. It’s believable.
That said, there are other ways to use the weather in your story. An overcast day has a different feel than a bright sunny day. You can use it as contrast. Have a funeral on a bright day. The mood of the character is somber but the day is bright and cheerful. Another way to use weather is to have it rain on the funeral, making the character uncomfortable and cold, as well as depressed. I attended the funeral of my nephew who died in a motorcycle accident. It was March. The sun was shining, but the temperature was about 5 degrees Fahrenheit (-15 Celsius). While the day was bright and we were all somber, we were also freezing.
Weather can help you set the tone of your story, make your character’s tasks harder, or just make things uncomfortable. A good storm can take out the electricity which can add tension to an already tense situation. Be careful though, storms can become cliché, just look at any horror movie. They rarely take place on nice sunny days.
Just a few words on the weather sprinkled here and there can make your story more real. It doesn’t have to play any more role than that, if you don’t want it to. Just know that weather happens pretty much everywhere and let your characters feel it, or even just check it to see if they will need a light coat, a rain coat or a parka that day. Is it raining too hard to go for a run? Perhaps the rain has caused a flood on the character’s usual route, forcing it to deviate and encounter an adventure. Perhaps a tornado sends the character to Oz.
Weather can be important or just incidental, but without it, the story will not ring true to your readers. You don’t have to spends pages on it, but a few references here and there can make the story work. Storm clouds on the horizon don’t always cause problems, but can increase anxiety. Bring the weather into your story. You will be glad you did.