I've lived in Lexington, KY for the last 20 years. Our hardness varies from 110 to 326 ppm. I have never used a water softener and I have the original water heater in my house. I lived in Cincinnati for 8 years and had to replace a water heater in that house, I think it was the original, looked pretty old. The house was built in the mid 60s. I think it weighed twice what the new one weighed. It still worked though.
I found this about the water in Tucson, apparently they are mixing water, something called a Clearwater blend:
The level of certain minerals in water, particularly calcium, determines how hard or soft the water is. The hardness of our groundwater varies from 68 ppm to 320 ppm depending on your location. The Clearwater blend initially had a hardness of about 80 ppm and rose slowly to about 180 ppm by 2011. https://www.tucsonaz.gov/water/clearwater-faq
Bottom line is, for a month's trip, you won't notice anything, I wouldn't worry about it.