The standard definition of a heat wave is one where the temp is 90 or above for three consecutive days. That seems reasonable, except for the fact that as we head deeper into summer, 90 is easier to hit.For instance, here in Allentown, PA, the average high today is 78. Getting to 90 for three straight days in early June is not easy, so I can accept the definition. However, in July and August, the average high is 83/84. Why is a temp only six degrees higher than average considered a heat wave?? Conversely, in January, our daily high is 34 degrees. No one would consider a high of 28 a cold wave. In fact, I have seen a high of 28 described as "seasonably cold"!! So, why isn't a high of 90 in July considered "seasonably warm" instead of a heat wave??