every once and a while, my city turns up the chlorine as part of some annual flush or cleaning or whatever.
anyway, the water coming out of my pipes is the exact same temperature as it always was, but for some reason it seems warm when I taste it. it doesn’t matter how long I let it run, it’s just the same on my tongue. I’m filtering it, I can’t even taste the chlorine, but it just feels tepid at all times
Probably the taste of dissolved gasses differs. Normally that is the main difference in taste between water of different temperatures thus we take it as a taste proxy for temperature.