Seasonal user ambient temps, due to weather, have nothing to do with manufactured hardware frequencies.
Processor companies do the same thing all the time (the only difference is they remodel the "weaker" ones - like Bitmain did with the S7-LNs):
Company X designs "xYz processor" to run @ 4GHz.
10% of chips will only run stable @ 3.75 GHz.
Company X sells those 10% as "xYzW processor" to run @ 3.5GHz.
Rather than "rebrand" weaker boards, Bitmain is just running them in small "batches" (rather than redesigning like they did with the S7-LNs).