Flights at this price open up around late January and are bookable through the middle of March, and if you are super flexible, you can find some dates that overlap with St. Patricks day. Departure dates are scattered, but I found most of the tickets at this price on Monday, Wednesday, and Fridays.
With a fare this low, there have to be some stipulations, and that is it books into Icelandair's "Light" category. Meaning only a standard sized carry-on bag plus one personal item is allowed onboard. If you need to check bags, consider paying for the standard Economy fare, which includes one free checked bag, bringing the total to $397 roundtrip, which is still a solid deal. If you want to break your trip up a 3-day stopover in Iceland on either the return or outbound leg of the flight is also allowed, a great 2-for-1 deal!
As an example, I found seats departing SFO on February 4 and returning from DUB on February 13, 2019.
We are seeing a lot of great deals to Europe today, so make sure to bookmark and have a look at all the other available destinations on sale on our European Flight Deals page.
Need a hotel in the Emerald Isle? Take a look at what's available on Hotelwatchdog for the provided dates.