What Times of Day Are Hottest and Coolest

In your weather forecast, high and low temperatures tell you how warm and cool the air will be during a 24-hour period. The daily maximum temperature, or high, describes how warm you can expect the air to be, usually from 7 a.m. to 7 p.m. The daily minimum temperature, or low, tells how much  the air is expected to cool, usually overnight from 7 p.m. to 7 a.m.  Ã‚   High Temperatures Dont Happen at High Noon Theres a common misconception that high temperatures occur at high noon when the sun is at its highest elevation. However, this is not the case.   Just as the hottest days of summer dont happen until after the summer solstice, high temperatures dont usually happen until the late afternoon — typically  3 to 4 p.m. local time. By this time, the suns heat has built up since noon  and more heat is present at the surface than is leaving it. After 3 to 4 p.m., the sun sits low enough in the sky for the amount of outgoing heat to be greater than that incoming, and so temperatures begin to cool.   How Late at Night Do Lows Happen? Just how long after 3 to 4 p.m. will temperatures be at their coolest?   While you can typically expect the air temperature to drop as the evening and nighttime hours wear on,  the  lowest temperatures  dont tend to happen until just before  sunrise.   This can be quite confusing, especially since the low is often listed along with the word tonight. To help make it a little clearer, consider this.  Lets say  you check the weather for Sunday and  see a high of 50 °F (10 °C) and a low of 33 °F (1 °C). The 33 degrees thats displayed is the lowest temperature thatll occur between 7 p.m. Sunday evening and 7 a.m. Monday morning. Highs Dont Always Happen During the Day, Nor Lows at Night Weve talked about the times of day when  high and low temperatures occur 90% of the time, but its important to also know there are exceptions to this.   As backward as it sounds, sometimes  the high temperature for the day wont actually happen until  late in the evening or overnight. And likewise, the low can happen during midday.  In winter, for example, a weather system may move into an area and its  warm front  sweep across a region late in the day. But by the start of the next day,  the systems cold front then enters and sends the mercury  dropping  throughout the daytime  hours. (If youve ever noticed a downward-facing arrow next to the high temperature in your weather forecast, this is what it means.)