What have been the worst weather conditions you’ve ever endured, and where were you? ~

An Ice storm in Illinois many, many moons ago. 

I was on the highway westward to Saskatoon one winter evening when a total white-out blizzard came up. "I can't drive in this kind of conditions;  can't even see the road". Then I noticed a red light appeared dimly ahead so I decided maybe i'll trust that to be my guide and try to follow behind. Finally came to the city lights of Saskatoon and could see fairly well again. "Where did my guiding light go?" It had totally disappeared. 
Maybe to guide some other highway traveller through the storm.

The blizzard of 78. I was at the Naval base north of Chicago.

A very big and scary typhoon on the island of Guam.

Summer of 1980, in the Atlantic, 75 miles off the southeastern coast of the US. First time on the ocean and the first time to see how large swells can become out there. We were on board a 65 ft. fishing charter in weather that actually should have kept us in port. The rain and wind were steady through the day and the conditions seemed to get worse at mid day. Since I'd never been on the sea and had never seen exactly what it's capable of, I'd have to say I was impressed. Strangely enough, we managed to catch a few fish. I've made a couple of trips since then, but this kid won't leave port if it's raining or looking like rain.

The temperature dropped below 70F and I darn near froze to death - California.

Widespread storms with high winds which brought down the power connectors and blacked out the entire State. I was down at the far side of town, working - had no idea how long it would last, waited until after my last appointment time had passed, then drove home without street or traffic lights as the grid was down.

https://en.m.wikipedia.org/wiki/2016_South_Australian_blackout This post was edited by Slartibartfast at July 28, 2020 6:39 PM MDT

I was about 12 when a small F-1 tornado came into our neighborhood. We never saw the funnel because it was so close. I did see the neighbor's garage go straight up and all the connected blue electrical flashing as the wires broke loose. Our swingset was knocked over. Our mobile home was unharmed.

Thirty-six hours of strong wind and driving rain while camping wild on a remote Norwegian fjell ("fell" if you're from Yorkshire - high uplands if from neither country!).

That itself would only have been unpleasant, if my small tent had coped with it. It didn't. That night I ended up wearing water-proofs inside my sodden sleeping-bag as the water dripped onto my head. I had dropped my camera in a stream and I had had that open to dry out in a corner of the tent - where it now lay in a pool of water.

The driest of the lot was a lemming sheltering under the ground-sheet.

We had a long, hard walk back down to the road, but luckily we were going down that day anyway, and I had a spare sleeping-bag in the car. The weather turned bright and quite hot again too, so I could dry everything over the next day or so.  

++++

That was only bad weather on a couple of days on holiday though; and I was able to recover the situation.

Far worse was the Winter of 1962-3, when even Southern England was gripped by a very unusually severe blizzard and the snow lay for quite some time. Two people died in their car not far from our town - trapped by drifts, they tried to keep warm by leaving the engine running, and were poisoned by the exhaust fumes.

A massive snowstorm that lasted about 24 hours and covered the UK for 2 weeks. Had to leave the car on way home and walk for nearly 3 miles! It was in 2009 I think.