A few things happen sometimes in terms of weird blooming.
This is getting rediculous....

Mums and Asters blooming. Typically never dead head to try for another later bloom - will this year.

What will be there in the fall? Hell - even late summer for that matter.

My liatris will be blooming in a week or so - August usually
And Goldenrod also looking like it is cranking up. Sept. usually.

I do recall blooming was all screwed up in 2011 and 2012 which for us were very hot (like now - 104 here today) and dry years. Combine the bad El Nino going to a pretty bad La Nina and it really messes up the weather (no winter per se) and plants.

David-- Here I get two bloom cycles out of hardy garden mums. Usually by mid-June I have to top them off for fall bloom. I do not cut the majority of them off. The only mums here that I see that have one bloom cycle are the less hardy florists mums. Crazy weather patterns. I would think you should get another bloom cycle out of your mum's. The florist mums in the ground here have not had a bloom cycle. Have a joyful weekend!

I've noticed that some things have been blooming hugely early, and others are not. Which makes me think that not all the plants are triggered by the warmer weather. Some of them must be tied to the time of year more solidly.

@Conniepr27 I believe you are right. My modern iris bloomed early. My historic iris held more to the actual calender dates of when it normally blooms. Asiatic and LA lilium were early, but Orientals were about right. Have a joy filled day!

Will have in addition Goldenrod blooming in 3 or 4 days. And Blazing Star within a week. I will have absolutely nothing for late summer/fall.

Cannas are above half bloomed. About a month early.

David-- Here we get two bloom cycles. On your cannas, you can top the flower and the first set of leaves under the bloom. It should force new growth and make that want to bloom. Maybe take your early blooming perennials and see how many you can force into a second blooming. It would be a nice interesting experiment. Many joys!