
Lightning touches down with a rain cell northwest of town on July 31, 2017, west of ÃÛèÖÖ±²¥, Ariz.
Since 2008, the National Weather Service has decreed a monsoon season from June 15 to September 30. However, it still keeps track of the  by a measure it used from 1949 until 2008 — the first of three consecutive days with an average dew point of 54 or above.
Also known as chubasco, the summer rains bring much-needed moisture and cooler evenings. Not to mention lightning, heavy rain, high winds, flash flooding, hail and dangerous driving conditions.