Interesting question !
I boarded a BA A320 in Bologna recently and both TE AND LE flaps were extended (temp was over 30C) Suspecting a technical problem (we only ever left flaps out on Boeings after landing on snow/ice contaminated runways) I asked the cabin manager if that was the case. After a flight deck visit she advised me it was SOP in hot weather to avoid a false warning and we departed on schedule.
Later my son- in- law (a former 320 TRE) confirmed flap extension in hot weather is SOP as told to me by the cabin crew !