We have taken the measurments of temperature, humidity, net radiation and pressure in our lab so we can calculate the potential reference EvapoTranspiration. So to find out the potential reference ET we have the minimum temperature and maximum temperature of each half an hour. same for humidity. My question is to find out ET per day, should I take the mean of minimums or the minimum of all? I have the same question for maximums. per day and per month. Thanks.