Until the bombs started falling.
They were used to warn of incoming bombing raids. The sirens could be heard over a wide area - and were more effective than (for example) making a radio broadcast.
Once enemy bombers departed the area, Civil Defense officials would use the Air Raid Sirens to sound "the all clear". This was a different sound than that the sirens made to warn of an air raid.
A series of air raids is known as a Blitz.
The sirens used during World War 2 were generally referred to as air raid sirens. They were used to warn civilians of impending air raids and to signal the need to seek shelter in bunkers or underground spaces. The sirens served as a crucial method of alerting the population to the danger of aerial bombings.
Germany
Air Raids could last from just afew hours to a whole night.
Sirens that could be heard through the city would go off to let people know that they should seek shelter.
In Britain they had many sirens to alert people to air raids.
They were used to warn of incoming bombing raids. The sirens could be heard over a wide area - and were more effective than (for example) making a radio broadcast.
Once enemy bombers departed the area, Civil Defense officials would use the Air Raid Sirens to sound "the all clear". This was a different sound than that the sirens made to warn of an air raid.
I should imagine the air raid wardens by sounding an air raid siren!
Who's air raids?
Air raids is a noun.
A series of air raids is known as a Blitz.
An air raid is when the enemy flies over the country they are fighting and drop bombs. Sirens go off to warn people to seek shelter, a dog fight is a battle between two airplanes that are at war.
The sirens used during World War 2 were generally referred to as air raid sirens. They were used to warn civilians of impending air raids and to signal the need to seek shelter in bunkers or underground spaces. The sirens served as a crucial method of alerting the population to the danger of aerial bombings.
They usually lasted for about 2 minutes