4+ mmm as in solid copper wire that is 4 mm in diameter.
That will earth lightning and remain intact. The experiments
recently performed in AZ used blunt rods and sharp pointed
rod. The purpose of a lightning rod is to earth a direct
strike. Lightning preferred earth via blunt rods.

Delicate electronics already has thousands of volts of
internal protection. This defined in manufacturer
semiconductor data sheets, required in IEC and other
standards, and is why we divert lightning to earth so that
electronic internal protection is not overwhelmed.

How well proven is the technology? The £multi-million
telephone switching computer connects to overhead wires
everywhere in town. Do they shutdown for each thunderstorm?
Of course not. They also use same 'well proven even before
WWII' technology. Protection of electronics is that routine
and that well established in virtually every town.

Protection of electronics in that weather station is defined
by the quality of and connection to earth ground. Lightning
that does not find a path to earth via electronics does not
damage that electronics.

Dave Liquorice wrote:
Blunt as in a straight cut or blunt as in terminating in a hemisphere?
Assuming by "rod" you mean something of circular cross section.
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Please define what you mean by "4+ mm".
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That is what I said.
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Delicate electronics does not take kindly to the huge induced voltages
that a lightning strike produces over several hundred yards distant.
Yes, you can build electronics that will survive but that does not
come cheap. In effect the electronics to read the sensors, convert the
data to a form suitable to be sent over a low power RF link cannot be
protected at a price the consumer is prepared to pay.
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