Reykjavík nightlife is compact and stubborn. Most of it happens within a four-block radius around Austurstræti and Bankastræti, and locals tend not to go out before midnight on weekends. If you are planning a late date, accept that you are going to walk between five places in the same square kilometer and that this is the point.
Kaldi Bar on Laugavegur
Start at Kaldi around ten. It is a small wood-panelled bar that pours its own beers from the Kaldi brewery up north, and the back room has couches that are good for actually hearing each other. The crowd is locals plus the occasional in-the-know visitor. Order a Kaldi Blonde and a shot of brennivín if you are feeling brave. From here everything else is a five-minute walk.
Pablo Discobar for the second drink
Up the stairs above Veltusund, Pablo Discobar is loud, pink, and tropical in a way that makes no sense in Iceland and works anyway. The cocktails are real cocktails, not novelties. Go around eleven thirty when the room starts filling up but before the line at the door becomes a problem. This is a good place to find out whether your date can dance, or whether they have opinions about disco, both useful pieces of information.
Kex Hostel late
Kex, on Skúlagata facing the sea, is technically a hostel but the bar at the back is one of the better late-night rooms in the city. There are old typewriters, mismatched chairs, and frequent live music that is not advertised loudly enough. The kitchen does food until late, which matters if your date forgot to eat dinner. The view out the windows toward Mount Esja is free and sometimes there is an aurora over the water if you are lucky between September and March.
A swim at midnight
Most of the geothermal pools close at ten, but Sky Lagoon out in Kópavogur stays open until eleven on most nights and the last admission is around nine thirty. If you plan ahead, the seven-step ritual, which includes the cold plunge, the sauna with the picture window over the Atlantic, and the salt scrub, is the most romantic thing you can do in this city after dark. It is not cheap, around 12,990 ISK, but it occupies two full hours and replaces dinner-and-drinks entirely. Book in advance for the late slot.
If you want the local version, Laugardalslaug is open until ten on weekdays and the hot pots are nearly empty in the last half hour. Bring your own towel.
A hot dog at Bæjarins Beztu, then a walk to the harbor
The last move of the night, at two or three in the morning when the bars are emptying onto Austurstræti, is Bæjarins Beztu Pylsur. The hot dog stand by the harbor has been there since 1937 and the line is part of the experience. Order eina með öllu, which is one with everything, meaning ketchup, sweet brown mustard, remoulade, raw white onion, and crispy fried onion. It costs around 650 ISK.
Walk it down to the Sun Voyager sculpture on Sæbraut. The steel ship faces the water and Mount Esja, and at three in the morning in May the sky is already pink again. This is the part of the night that people remember.
A few practical notes
Icelanders pre-game at home and arrive at bars late. If you show up at nine, the room will be quiet and you will think you picked badly. You did not, you are just early. Cash is essentially gone, every bar takes cards, and tipping is not expected.
Weekend nights downtown can get rowdy around two when the clubs empty. Kaldi and Kex stay reasonable. Avoid the bigger Austurstræti clubs unless your date specifically wants that energy.
If the aurora forecast is high, all of this can be replaced with driving fifteen minutes out of town toward Grótta lighthouse and turning the headlights off. That is the unbeatable late-night Reykjavík date and the only one that requires a car.