Ebay has a great selection of thermometers and hygrometers. I was having so many temperature issues that I bought several cheep thermometers of different kinds two came from TSC. Those two were made for hatching and were 5 degrees different. My two good digital weather station thermometers were also several degrees apart. I finally invested in a non-digital one that could be tested. It was perfect then bought a good digital also. So don't assume anything is accurate if you can't test it. Thermometer test - fill glass with coarse ice, put in water to just top of ice and stir with thermometer till temp settles. If should read 32 degrees. Test for hygrometer - http://www.burgessviolins.com/calibration.html