热穹顶通常指当炎热天气在某一地区停滞数天或数周时的现象。它的形成原因在于地表暖空气被困住而无法上升，从而导致局部持续高温，这种现象往往引发称为热浪 (heat waves) 的异常高温天气。

THE HAGUE, July 2 (Xinhua) -- The Netherlands has been hit by its first official heat wave in three years, prompting the Royal Netherlands Meteorological Institute (KNMI) to issue an orange code alert ...