Why are Northern Daily Temperatures So Constant?

In the Sahara Desert, daily temperatures can range from blazing heat at midday to near freezing at night. Here in the North, we normally experience comparatively mild fluctuations during a 24-hour period. Why the discrepancy?

The answer lies in the fact that the angle of solar elevation varies little during the day at high latitudes. At the equator, the sun is directly overhead at noon every day of the year, and disappears completely during the twelve hours of darkness at night. This creates the extreme in temperature between day and night.

In Alaska, the situation is obviously different. In winter, the low sun angle provides little heat during the day, and during the summer, the sun circles around the horizon, changing little in apparent elevation. Thus, there is comparatively little change in temperature during a 24-hour period, except for those times when a weather front is approaching.