It’s All Downhill From Here That sounds rather dim, but if you’re feeling heat fatigue, it’s a sliver of good news. As we watch a heat wave expand out of the South into the Midwest and Northeast this week, we’ve reached what is typically the hottest time of year in most of the U.S. That means daily average temperatures (highs and lows) reach their peaks from late July into early August in much of the country. For example, Kansas City’s hottest daily average high temperature is this week, before their average temperatures start tumbling into fall, then winter. In the mid-Atlantic and Great Lakes, that hottest time of year was in mid-July. Parts of the Deep South reach that annual peak in early August. The sun is highest in the sky over the Northern Hemisphere on the first day of summer, around June 21. The reason the hottest time of year lags the summer solstice is it takes time for the sun to heat the land and any nearby water, then the air above it. There’s nothing magical about these daily average temperatures. They are just averages. If a particularly strong heat dome of high pressure sets up, a city could have its hottest day of the year in, say, late June or mid-August. There’s plenty of heat left in the summer, of course. But as sunrises tick a bit later and sunsets a bit earlier each day, it’s a reminder that a change of seasons isn’t as far off as you might think. |