Cucamonga in June is hot.  This was the first peak I solo hiked on purpose (I inadvertently hiked Sitton alone when a friend missed a message).  Truth be told I'm glad to have hiked it that way.  It was a tough climb, but I took it fast. When I needed to rest I did, but I rarely need breaks.  Given the heat I was glad to only have to concern myself with my own condition. I brought less water than needed, as the descent is long, exposed, hot and uneven, so challenging.  I went through 2.5 L and was out of water with 3 miles to go.  3+L is necessary. Cucamonga would best in spring and fall with heat in summer and snow in winter.