I am not sure if that is the case. I live in Southern California where the weather forecast stays pretty constant so there isn't much change in the hi low temps. I think the hi temp is changing as the day progresses. For example, this morning the hi on the watch was 72. It stayed this way for most of the day until the sun started to set. Now, at 5:30pm the hi is 66. This behavior makes sense to me because it wouldn't be very useful to show the hi temp that has already past.
