Yes, this is the summer rainy season, which arrives (along with thunder and lightning) at the hottest time of the year. Its effect is to turn the dry summer desert green in August and September.
The other hot deserts in the southwest have only one rainy season. In the Mohave Desert, most of the year's rain falls in winter. In the Chihuahuan, it falls mostly in the summer. As a consequence, these deserts have a more sparse and less diverse vegetation than the Sonoran.
