Three people have died and 450 others were injured after being stung by scorpions in the city of Aswan, according to officials.
The attacks happened after rainfall, thunder, dust storms, and snow hit the region in the south of Egypt.
A spokesman for the health ministry told Al-Ahram news agency that rain had flushed scorpions and snakes out of their hiding places, caused power cuts, and led many lighting columns and trees in the streets to fall.
Hospitals across the region are on high alert, doctors have been recalled from holiday and extra supplies of anti-venom have been distributed.
The governor of Aswan, Ashraf Attia, has urged people to stay at home and avoid places with trees.
The Egyptian Meteorological Authority (EMA) said the poor weather is likely to continue for the next 24 hours.