Re: Cells emerge early
Exactly why I have an incubator also. Haven't had my incubator long but soo pleased with it should have built one years ago.
However a few things to think about. Brood nest temperature according to my testing plus some research, mostly varies between 94 and 97. At the warmer end of this the queen cells can develop faster. And your hive would have been at the warmer end in the out door temperatures you describe.
Secondly it is said that from when the egg is laid, the cells hatch on day 16 + or - a day. Which best I can tell is pretty accurate. However for me, before I had an incubator, In mid and late summer when temperatures were high I used to plant the cells a day early cos there were just too many incidents of at least one of them hatching early. And I do know how old they are because the eggs I use for queen raising come from a comb that is only in the breeder queen compartment for 24 hours. I can say as a fact that in hot weather there is a risk some of them will hatch on day 14.
Only other thing, if you grafted from comb in the brood nest, it is possible some of the larvae were a little older than you thought, add that to all the other factors & you could seemingly have queens hatching on day 13.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).