You are having our late May temps.I've taken to the Spanish approach. we get up early, I work in the garden until around 10am unless I have any cooking to do then I stop at 8am and cook. anything much past 10am is now not enough to have doors, windows and heat shielding curtains closed. internal doors also seal off the laundry room and sun room (blinds down permanently atm). it stays like this until around 6pm when I've usually lost the battle and the internal temperature is around 30C matching outside. at which point you may as well make use of the fresher air outside and open doors, windows and curtains until 6am the following day. we are going to bed with temps of 28-30C, waking up with +20C. it's due to get hotter soon as summer progresses. we are at the equivalent of end of June in the northern hemisphere seasons. 35C is current daytime temp, though today it is only at 32C but it is only 3pm right now. still time to get warmer but humidity is very high today at 60-70%. thunder is forecast but we can't see it happening. tomorrow is meant to be hotter.
As for water, well one of the major differences here is that we celebrate when it rains! totally private water means we only have what we collect and that is rain water for drinking, dishes and shower plus hand washing. washing machine, toilet and all stand pipes are bore water which is brackish. plus the spare buildings are also on bore water as well.
I rarely water the veg plot. most water is recycled in that I collect it and use it for watering the garden including the veg plot (by hand). so any water going down into the septic tank really is waste water, not just grey water. collected water is hand washing, veg washing, dishes and anything I can when showering. it is carried down to the plants that need it. something gets watered 4 or 5 times a day. I only carry out small quantities at a time (unable to lift) but I keeps plants going until it next rains, mostly.
it works for me and I'm used to it. most people couldn't hack it for long even if they picked up the guts to try in the first place. but if everyone lived rurally there wouldn't be any rural.
Though one day last week we had your evening temps as high.