The weather may be the most widespread topic of conversation in areas where the weather is changeable. On a chilly wet day, we may exchange comments with strangers under umbrellas at the bus stop; or start a conversation about the heat as we drop onto a shared seat after jogging around the park.
One of my personal writing-related files contains sections in which I jot down words or phrases which interest me. I use the three hand-written pages of weather-associated words for ideas, to edit and re-write as necessary for the weather to fit or augment the plot and the characters, and to help me avoid cliches such as lashing rain, howling gale.
Those weather conditions in which we situate our people are usually there for a crucial reason: have them enjoy, or struggle against, to stop them from doing something, to put them in danger, to act as a source of tension between them, and ultimately to move the story along. Such circumstances create atmosphere, physical and/or emotional, affecting characters' moods, influencing the plot. For several of the weather episodes in my novels, I've needed to do considerable research, which for me is always an enjoyable task. I do some on line from weather and news reports, and from reading and viewing local information, and where possible from visiting the area.
During a trip some years ago to the Eastern Caribbean, I had no thought of setting a novel in a location entirely exotic for me; the contemporary romance Where the Heart Is emerged later. While I gave Cristina a dreamy Caribbean beach (plus a dreamy man) in gorgeous weather, I also involved her in a hurricane with a perilous wet and windy mountain rescue by motorbike. I didn't experience the extreme weather event I put her and the motorbike rider through, but I did gain background knowledge valuable for future use. And in this story, the sub-tropical climate contrasts with the temperate spring of her rural Australian home.
Hoping your weather is kind to you, Priscilla