There's no strict rule. The easiest cue is the weather rather than the calendar, so once mornings and evenings turn consistently cooler, it's a natural time to reach for sweaters, long sleeves, and warmer layers. Many people start transitioning in early fall by mixing lighter seasonal pieces with their summer staples, then layering up as the temperature drops. Dressing for how it actually feels outside keeps you comfortable and lets you enjoy your fall wardrobe longer.

Transitional weather calls for flexible layers you can add or shed as the day warms and cools. We'd reach for a long-sleeve top or light knit with a vest or unlined jacket for those in-between days. Mid-weight fabrics keep you comfortable when mornings are crisp but afternoons still feel like summer. A layer from our jackets and vests is an easy way to bridge the two seasons without overheating.

Start with a comfortable base like a short-sleeve tee or a light long-sleeve top, then add a cardigan or lightweight sweater you can take off if the day warms up. We'd keep the base thin and the top layer easy to remove. That's the key to staying comfortable through changing temperatures. Layering also lets you shift a summer outfit into fall simply by adding a knit or vest over pieces you already wear.