Technology impaired by bad weather?

A few years ago, when I was working for a large company, i remember the head of HR being adamant about internet not working so well when it was raining. I used to laugh at her. Come on, technology stands on its own. Rain or shine.
Yet, I may be changing my mind in light of the latest Eurostar misaps. My gf takes the Eurostar every weekend to come to Paris so I am acutely aware of the train problems. And today it stayed stuck in the tunnel for 2 hours... while it was snowing outside. A few months ago trains were stuck all night in the tunnel while we had a cold wave in Paris. Etc. So you tell me... cold weather stops high tech trains?