Low urine output in hot weather is usually normal, but if it is less than 400ml per day, it is abnormal. It is normal to urinate less if there is not much water intake. Furthermore, in hot summer weather, water will be evaporated through the body surface, as well as sweat, etc. will take away a lot of water. When water is taken away from the body through these channels, the amount and frequency of urination will naturally decrease. This is normal if it is not accompanied by other discomforts and will improve after drinking water. If the amount of urine is less than 400ml per day, it may be pathologically low, and if it is combined with other symptoms such as frequent urination, painful urination or even hematuria, it is necessary to consider a urinary tract infection. If you have a low urine output with other discomforts, it is recommended that you consult a doctor in a timely manner, follow the doctor’s instructions for relevant examinations, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.