I have climeb for decades and therefor feel qualified to answer this question. The bottom line is if YOU don't know what you know or what you don't know, assume you don't know enough. If you do think you know all that you need to know then stay home until you are no longer over confident.
When it comes to weather, you don't know unless you are there. I I was once hammered so bad I truely though I was going to die soon. We dropped a few hundred feet to find campers in mild conditions. They called us pussies and finished packing for the summit and headed up the same time we headed down.
Since I didn't read about them, I assume they either turned around or didn't have any loved ones to report their absence.