Hi @antobaro ,
Thanks for writing in with your question.
In your case, UHImax equals the maximum temperature observed in the city during the period of interest (the last 3 years), during day and night, respectively, MINUS summer Tair,ref for day and night, respectively. I suppose you are correct in that you probably ought not subtract the maximum value ever recorded there if you are only interested in the last 3 years. Perhaps the User Guide language could be more precise here, but all input data should be relevant for the temporal period of interest (only). So if you’re interested in the last 3 years, only input data from the last 3 years. If you’re interested in summer, only use data from the summer. When investigating night versus day, be sure to differentiate your input data so that they only cover night and day, respectively. The model is time period agnostic, so it’s up to you, the user, to ensure the data cover the appropriate period. The only time-related element the model distinguishes between is related to the calculation of cooling capacity. For daytime calculations, be sure to rely on shade, albedo, and ET index values, but for nighttime, these factors are irrelevant of course, so instead be sure to use data on building intensity. But again, the model is unaware if input data cover day or night, so the user must manually adjust and select the appropriate method.
You may also find these other forum posts useful:
I hope this helps your understanding,
Jesse