What Is the Definition of a Heat Wave?

Satellite imagery shows our beautiful, green country now looking brown. And accompanying this heat way, we've also got a drought. All our gardens are parched, and to agricultural struggling. So what is the actual definition of a heat wave? Sirn well, so there are lots of different definitions of heat waves actually used throughout the world. In england, we have a threshold based definition, so we talk about when temperatures exceed, say, 28 degrees or 29 degrees. But even that threshold base definition in the uk. Varies cross the u.K., lower in scotland and it's higher in england.