I am going to Iceland this weekend, any advice on weather, lack of daylight, northern lights and outdoor swimming.
I'm looking forward to it, sadly not much available in books or videos. Sadly, the only place Rick has no guidebook on.
Iceland (and Rekjavik) has excellent web resources for visitors - start there. Or pick up a Lonely Planet book.
You could also check out Trip Advisor. There is a well-used forum for questions, like the Helpline here, and then lists of attractions, tours, hotels, and restaurants with reviews. This is certainly what I would be using if I was going there.
http://www.tripadvisor.com/ShowForum-g189952-i223-Iceland.html
I would like to help you but I was there in July and it was (almost) like January in Seattle. Maybe little bit less rain but not much. Look on this Travel Helpline under Trip Reports. There is a report on Iceland in December. I can imagine that January will be somewhat similar.
To answer your question re lack of daylight: Yes!
Looks like you are the Iceland in January pioneer. We hope you will do a trip report for the rest of us.
I just came back from a trip to Iceland and London! Iceland was absolutely fantastic, I'm so very glad I chose to go in winter.
Be prepared for it being dark. I knew the sun rose later, I just didn't realize how completely different it would be. 11am sunrise, 4pm sunset, though every day it is staying lighter 6 minutes longer! The hardest part about the short daylight was trying to fit all the sightseeing in while it was still light out.
As for weather, it was between 30s and low 40s when I was there, which was a whole lot warmer than the polar vortex weather that I missed! The wind though will go right through you, so make sure you wear lots of layers and windproof layers. There was no snow and no rain, just cloudy with bits of sunshine. I was really glad there wasn't snow on the ground, as it would've detracted from viewing a glacier.
The Northern Lights did not come out to play when I was there; I had four nights and tried each night, but it was pretty much full cloud cover all over the southern part. Are you renting a car? I didn't rent a car since I was going solo and I wasn't sure what the roads would be like. So I was stuck with tours; but if you rent a car you can watch the forecast and then drive to wherever it looks like it will be clear. I was really pleased with all the tours I took; I did a full day Golden Circle tour, and a two-day tour to Jokulsarlon to walk on a glacier and it was really awesome. Then just wandered around Reykjavik.
For outdoor swimming I went to the Blue Lagoon; there are other outdoor thermal pools you can visit, but it was just perfect with my schedule to make a stop there on the way to the airport before my flight to London. Reykjavik Excursion has a package that includes pickup at your hotel, basic admission, and then drop off either at the airport or back at your hotel. It was an interesting experience running through 35F air into the warm water. Very relaxing; in all I spent about 3 hours there.
Oh and be prepared for it to be expensive. I read that it was expensive, but didn't realize just how very expensive everything is!
If you have any specific questions, let me know and I'll try to answer the best I can!
It is unfortunate that Rick is shunning Iceland (I believe he even said in a "recent" radio show/podcast, he discussed a layover he had there, and he mentioned that he doesn't intend to ever do a book on Iceland), but I would suggest the Lonely Planet guide to Iceland. I picked it up for our upcoming trip, and it looks like a great resource. I did not specifically look for information on winter weather, as we are going in May, but perhaps you can stop by a bookstore and take a look at the book before getting one?