Can the weather affect my body language?

The weather can affect almost anything in life, from the externals—such as picnics and outings—to the internalssuch as how you feel. Barometric pressure can inflame our joints and cause extreme pain when we move. Sometimes, however, the pain is minimal. We may not be consciously aware of it, but still our movement, our body language, is restricted. We become less outgoing and withdraw more into ourselves.

As a scientific fact to lend authenticity to the effect of weather on body language, a research study done with hidden cameras on cloudy, sunny, and rainy days, concluded that in bad weather people talked to each other less, smiled less, and used more restricted body language.

But we don’t really need scientific studies to tell us this. 

We all know that a gloomy day affects us and depresses us, while a mild, sunny day exhilarates us.

Your girfriend was simply stating a basic truth about the weather and body language—or how people feel.