I have a pothos that lives in half gallon jar of water.
It used to live outside on my patio that got morning and early afternoon sun in Central Texas where the temperatures were getting in the 90's, the dew point was in the 70's and the humidity usually is 40 - 60% typically, though weather underground tells me it was closer to 90 - 100%.

My jar of water would last for weeks before it noticeably evaporated and had to be filled.

Anecdotally the plant lived in doors in the jar with much less direct sunlight and a near constant temperature of 70 degrees from the AC and I never had to fill it up.

Flash forward to now, I am in South East Louisiana, my jar of plants is inside in a windowsill that gets morning sun. My AC is bad so it gets up to about 84 in here.

I am noticing that the water is receding quite rapidly, it is noticeable within a few days and at least once a week I need to get water in there to cover the top roots again.

The humidity down here is much higher so I am curious, why would it be evaporating so much faster down here where it is much more humid presumably? Any ideas?

Edit: I should probably add it is growing algae now too and that was never a "problem" before.