This timeline shows the day length (hours between sunrise and sunset) for an entire year in three locations: San Juan, Puerto Rico; Boston, Massachusetts; and Fairbanks, Alaska. Note that there is much more variation in the day length in Fairbanks, which is near the arctic circle, than in San Juan, which is closer to the equator. On the winter solstice, the day length in Fairbanks is less than 4 hours.