POLAR CIRCLE MARATHON, THE COOLEST MARATHON ON EARTH 

Hello, I did both the marathon and half-marathon here in 2016. You will need a windproof and ideally also waterproof top layer. A proper waterproof, windproof running jacket should be your top layer at all times, I had a full-sleeve running base layer and a close-fitting activity fleece below it. For my legs, I had a long set of thermal leggings and a pair of waterproof, windproof Berghaus hiking pants. I had one pair of waterproof socks (I used a neoprene brand called Roosters designed for sailors) and a pair of merino socks over the top for warmth. As a rough rule of thumb, three layers on your torso and two on your legs is probably ok with a windproof, waterproof top layer. You will need two pairs of gloves and two pairs of socks if the conditions get tough. You will also need portable crampons. A good outdoor goods store will sell them, these will fit onto running shoes and can be taken off if needed. There are also three stop points for personal provisions on top of the refreshment stations. The best advice I can give you is to get three small flasks, and prepare a warm isotonic drink for each one. As well as those, put in a spare pair of socks, a spare set of thin gloves, a small snack, and a spare Buff (neck covering). There's probably more to say, but hope that helps for now.