Did you generate that from the BizEE degree days page? Degree days are (degrees over the set point)x(number of days). For instance, that 608 for August tells me that since August has 31 days, the monthly average temperature is about 20 degrees higher than the set point you picked. That is a load on the A/C system, but it doesn't sound too bad.
has been with concrete
block buildings, a high thermal mass, but not nearly as much as adobe. In the low desert of California and Arizona, daytime summer temps are always over 100F, sometimes over 110, but they seem to radiate the heat away at night and are comfortable without the air conditioning running all night. It's only when the temps start hitting 120F that the A/C seems to get overwhelmed and runs all night.