“Is it dangerous to make a landline phone call during a thunderstorm?” It can be. Background is provided by Emeritus Professor Mat Darveniza, AO, FTSE, BE, PhD, DEng, Hon DSc (Eng), FIEAust (Hon), FIEEE (life), FTSE, LIVA, from the University of Queensland Australia – who is a leading authority on lightning strikes.
In Australia alone roughly 30 people per year suffer lightning shocks delivered by telephone. The electric current is several orders of magnitude less powerful than a direct strike, but can still run to hundreds of amperes – and transferred, via the telephone cables, directly to “… a rather sensitive part of the body” – explains the professor in this piece for Channel 7, Perth.
Advice on how to avoid being struck by lightning (via your phone) is provided by Australian telecomms firm Telstra, in their lightning protection brochure : along with info on the related phenomenon of Acoustic Shrieks.