風が強いから

「〜ので」 means 'because ~' or 'so ~'. It functions as a conjunction that explains the reason or cause for the statement that follows. It's often considered a slightly softer or more objective way to state a reason than 「から」.

「〜ので」は「〜なので」という意味。理由や原因を示すが、「から」より丁寧なニュアンス。