Dress according to the weather, the weather can change very rapidly depending on if it's winter or summer. You should always wear good shoes or boots for your maximum comfort. Wearing three layers of lightweight upper body clothing is the most effective method for retaining warmth. The weather is so unpredictable in Iceland. it's always good to bring more than you use just in case.
● Base layer – normal underwear and short or long-sleeve t-shirts are usually fine
● Warm sweater – wool or fleece
● Lightweight outdoor trousers/pants
● Lightweight waterproof jacket with hood - rain – and windproof shell
● Good hiking boots - water-resistant
● Hat, scarf and gloves/mittens