If you’re planning on visiting Norway, and your schedule is flexible, then definitely try to visit during mid-May.
The best day to be in Norway, is May 17
May 17 is Norway’s national day — all schools, and businesses are closed, except for bars and restaurants (so only fun times on May 17). Everyone dresses in the traditional Norwegian clothing, and depending on where in Norway the person is from, determines the colors and patterns
Below is a picture of me (the only one not in traditional Norwegian clothing) when I lived in Stavanger.
Later on, I lived in Trondheim and got to experience May 17 again =)
Now, I’m living in Oslo, and host 17 Mai at my apartment because I live one block away from the king (where the parade route is – biggest in Norway).