Why do the Medina and Al-Ahsa dates precede the Qassim dates?

Weather of Arabia - Dr. Abdullah Al-Misnad, former professor of climate at Qassim University and Vice President of the Saudi Weather and Climate Society, said that the first dates in Qassim are usually displayed on July 1 of each year, with time changes of up to about a week, depending on the temperature changes. Al-Misnad explained through his account. The “X” platform should pass through Medina and Al-Ahsa a few weeks before passing through Al-Qassim, due to the greater accumulation of heat in these areas compared to Al-Qassim.