We are arriving in Amsterdam on May 21 and will be there until May 29. I know you can't predict exact weather, but what will the daytime temps be like? We are trying to figure out whether to pack for cool weather or warm weather. Shorts or long pants? Closed shoes or sandals? We also are planning to bike north of the city while there and need to figure out whether to wear bike shorts or long pants. We want to pack as little as possible!