Apple says the safe ambient temperature for your Mac is between 50° and 95°F (10° and 35°C). Since the temperature of your environment directly impacts your Mac’s temperature, make sure you don’t leave it in the sun or in the fridge (well...who knows). In other words, protect your Mac from extreme heat and cold.
However, normal CPU temperature is a different thing and really depends on your Mac model and what types of tasks you solve. Some M1 Macs can function quite well with up to 90°C, so we recommend that you look at the big picture with iStat Menus. Mac temp monitor alone won’t give you comprehensive insights as to your Mac’s performance.