Iceland's winters are not particularly cold but accompanied by strong winds and in the summer the weather is cool and pleasant. Just for comparison, an average temperature in winter in New York is lower than in Iceland. However, the weather in Iceland is known to be unstable. An important rule to use in Iceland - no matter how hot it looks outside, it is always better to take a jacket and not just in case. Or as the Icelanders say: "Do not trust the sunlight reflected through the window."
Iceland's climate is changing each season of the year and the length of day and night is changing too, which creates unique climate effects. Mid-winter period when the sun does not shine and the darkness dominates for most of the day, is an excellent time to watch the impressive phenomenon of the northern lights (Aurora Borealis).
During the summer time between June and July, when the sun dominates in the sky and shines through days and nights, you can watch the midnight sun shines in the sparkling colors of red, blue, gold.