It’s very unlikely in normal UK conditions, since the alcohol content in most perfumes gives them a much lower freezing point than water, but genuinely extreme cold, well below what the UK typically sees, could theoretically affect a formula.

Why alcohol changes the equation

Most alcohol-based perfumes are around 70 to 90 percent ethanol, and ethanol has a freezing point far lower than water, roughly minus 114 degrees Celsius in its pure form. In practice, a perfume left in a genuinely cold car overnight in a UK winter, even a properly bitter one, won’t freeze, though it may become noticeably cooler and slightly less expressive when first sprayed. Oil-based perfumes and attars behave a little differently, and very cold conditions can occasionally cause some oils to thicken or cloud slightly, though this usually reverses once the product warms back to room temperature.

The real risk in cold weather

Repeated temperature swings, warm house to cold car and back again, are more likely to affect a fragrance’s stability over time than a single cold snap. Consistent storage matters more than any one cold day. Our perfume storage guide and complete guide to perfume cover this in more depth.