To describe the temperature in Engpsh from high to low, you can say "the temperature decreases" or "the temperature drops." For example: "The temperature was in the high 80s today, but it's expected to decrease into the low 70s tomorrow." Alternatively, you could say "the temperature gets colder" or "the temperature falls." For example: "It's getting colder outside, the temperature has fallen from 75 degrees to 50 degrees in just a few hours." You could also use specific temperature words or phrases, pke "hot, warm, mild, cool, cold" to describe the temperature as it changes from high to low. For example: "It was hot and humid today, but now it's cooled off and feels more comfortable outside."