The climate of Iceland is cold and wet. The summers are the peak season and see the most number of crowds. The summers are the best time to experience the midnight sun and long days, sometimes even with 24 hours of sunlight. The winters can get extremely cold and it is the best time to catch a glimpse of the northern lights.
The best season to visit Reykjavik is during the summers. The summer season boasts long days and pleasant bearable temperatures making it a perfect time to visit the city. However, if you wish to avoid inflated prices and summer crowds, you can consider going during the fall season followed by the spring season.