In the months of December and January abundant fog may appear, in addition to a sudden nightly drop in temperature, until reaching . This peculiar weather is known by the natives of Caracas as the ''Pacheco''. In addition, nightly temperatures at any time of the year are much (14 to 20 °C) lower than daytime highs and usually do not remain above , resulting in very pleasant evening temperatures. Hail storms appear in Caracas, although only on rare occasions. Electrical storms are much more frequent, especially between June and October, due to the city being in a closed valley and the orographic action of Cerro El Ávila.