The climate in Iceland is somewhat harsher than the normal northern European or American climate. The wind can be very strong, temperatures may range from 5°- 20°C (40°- 70°F) and it can rain a lot, sometimes almost horizontally.
In the winter time you may expect snow and frost, most of the time though not much colder than -10°C on lowland, but in mountains, glaciers or inland it can go much colder. This frost is often however accompanied by some strong winds, increasing the wind chill dramatically.
Thus we must stress the need for warm clothing, at all times, although the weather can be changeable in summer, so the layered approach is the best. Rainwear is absolutely necessary and best watertight properties (otherwise it may leak)
Please wear good shoes. City shoes or/and sneakers are best kept for that use. You need good soles and watertight shoes, the gore – tex variation is the best, since the ground in Iceland is very often wet and marshes and brooks common, even at the most popular tourist attractions. Paths are limited and you may have to walk in stony terrain. Paths, where they exist can also be quite slippery and a good walking stick is a good investment. It is easy to lose one’s footing here, and we are not liable to accidents caused by bad shooing.