Dress for the whole route
A cold journey to the airport and a warm destination can make a single outfit difficult to judge. Divide the route into the parts you can predict: getting to the terminal, waiting, the flight and leaving the destination airport. Then decide which layer belongs to each part.
The base outfit should be comfortable for sitting and suitable to wear without the outer layer. A removable shirt, cardigan or light jacket can cover the uncertain temperature of the cabin. Avoid relying on one heavy coat if you will have nowhere convenient to put it after landing.
Give the extra layer a place
Check that your hand luggage has room for whatever you plan to remove. A coat draped over an arm may be manageable for a short journey but awkward while handling documents and a suitcase. If it must travel with you, consider how it will be carried before adding more items to the bag.
Keep the clothes simple to rearrange. A layer that requires a mirror, a belt change or several tiny fastenings is less useful in transit. You should be able to take off the warm part while keeping the rest of the outfit intact.
Choose the shoe for movement
There can be more walking than expected in an airport. Use a pair you know fits comfortably and stays secure. Check any airport or airline instructions relevant to your journey directly rather than assuming one travel routine applies everywhere.
A change into sandals at the destination may suit the weather, but pack them where you can reach them without unpacking everything. Keep the original shoes contained so they do not sit against clean clothes. Do not choose the departure outfit solely around the footwear you hope to wear later.
Think about the return journey too. The warm layer that felt unnecessary during the trip may be the first thing you want when you get home. Put it somewhere easy to find before packing the final souvenirs and laundry around it.
