Here in PA, we had a "Heat wave" of 90+ days for 3-4 straight.
My nomal FC usage until then was 1.6-2.0ppm...
During the heatwave, it jumped to 3-4ppm...3.8ppm the one day. I'd add to get it up to 8.8 or so...and by next day, sun down I'd be at 5 again.
Pool temp was 84, bright sun...no...