As it has already been stated, people will interpret "hot" differently. What one person thinks is too hot and uncomfortable may be perfect and ideal to someone else (same thing with the cold). It largely depends on what you are personally accustomed to and what your preference is.
If you are someone who loves the sun, then an 80-degree day will be wonderful. If you are someone who is extra heat-sensitive and tends to get sick after only a few hours in the sun (that would be yours truly, and it happened to me twice in just the last few weeks!

), and you prefer the Fall & Winter months, then 80 degrees can be unbearable.
If you are used to 100-degree temperatures, then 80 degrees will seem like an arctic chill.
Typically, June is not all that hot as far as SoCal summers go. We often have the dreaded "June Gloom" (which I love!

).
We seem to start picking up the real heat when August rolls around, and then sometimes it can be really hot in September (a couple of years ago it was something crazy like 113 degrees).
But..every year is different. Some years it seems to be exceptionally hot for SoCal. Other years it seems to be unseasonably mild for SoCal.