How old is your tree? Is it in ground or potted? I am in 8a and they usually bloom now but my tree's are younger (2-4 years) and have a mind of their own when they bloom. I'd leave the flowers because your tree will just make more if you try and take them off. If for some reason you don't want fruit after the fruit has set and is marble sized thin out as much as you want, I'd let the tree self thin then see what was left.

global cooling like in the 70s

Mine has also been in the ground 4 years. Global cooling seems unlikely for me, because it was a very warm winter here. Strange magic.

It was a much cooler and wetter winter here than it has been for the last 5 CA drought years, but the Meyer, Gold Nugget and Cocktail Grapefruit all bloomed and grew on schedule.

Some citrus are alternate bearing, so that may have something to do with it. Young trees take a while to settle into a routine also. Many of my trees have fruit ripening out of their usual season as a result of this. They are giving me fruit in summer which is nice.

Cory

Honey Mandarin doing the same also. Zone 10a, in LA area.