Stupendously average or less June.

What's the problem with fixating on the temperature? Us Brits are renowned for being fixated on the weather, so why not you? Low 70's sounds ideal for me, dislike the heat and the last few days have been too hot and muggy, cooler today thank goodness. Keeping plants alive is a challenge, especially baskets and pots when you get baking weather. Have at last decided that the hanging baskets will not survive where the previous owner put brackets, they just bake all day. I have tried it for years, but it's impossible - so why have I carried on trying? Take the brackets down and move them somewhere more sensible and stop fixating on that too!!

Its the whole thing about this climate. People who just want mild temps and sunny rain free days rate Hayward highly.

https://www.bestplaces.net/compare-cities/hayward_ca/los_angeles_ca/climate

I know my father loved it for working on the house. But,being I'm not a traveler Honey,I guess I never realized how hot it is where these plants I buy originate. The tropics are warmer in their winter then we are here in summers.
My relatives in Florida that visited last week liked the cool since its 90F or 33C and 90% humidity in south Florida right now. But,he grows a great Mango and Coconut palm-ha.

Everybody is complaining about the temps... Personally, I find the 20's C. quite comfortable. There is such variation in our temps. (for instance, our night temps have been in the single digits C. for more than a week, with a very cold north wind) I have peppers and tomatoes in my garden who have been set back by this. The peppers need night time temps in the 20's to set blossom. Cool weather crops like peas and lettuces are quite happy though.
Wow... what a dream...growing your own mangoes and having a coconut palm?! how lucky they are ..90% humidity is very uncomfortable though... like taking a bath with your clothes on! Couldn't live in a hot climate.