A bread recipe that works reliably in one place can fail in another without any change in method. Fermentation and hydration are both sensitive to ambient conditions, and neither is usually specified in a recipe.
Fermentation runs on temperature
Yeast activity roughly doubles with each modest rise in dough temperature within its working range, so a warm kitchen ferments dough substantially faster than a cool one.
A recipe stating a rising time assumes a temperature it rarely names, and following the stated time in a warmer room over-proofs the dough.
Experienced bakers therefore judge by the state of the dough rather than by the clock, since the dough reports the actual conditions.
Over-proofing damages structure
Fermentation produces gas that inflates the dough and acids that gradually weaken the gluten network holding that gas.
Past a certain point the network can no longer support the gas, and the loaf collapses in the oven or spreads rather than rising.
This is why the same dough can be under-developed in winter and structurally exhausted in summer using an identical schedule.
Flour absorbs water from the air
Flour stored in humid conditions takes on moisture, so a weighed quantity contains less flour and more water than the same weight stored dry.
A recipe specifying a fixed hydration therefore produces a wetter dough in a humid climate and a stiffer one in an arid climate.
Bakers working across seasons hold back a portion of the water and add it once the dough has come together, adjusting to what the flour actually needs.
Wheat itself varies by region
Protein content differs between wheat varieties and growing conditions, and higher-protein flours form stronger gluten and absorb more water.
A recipe written for a strong flour behaves quite differently with a softer local one, producing a slacker dough and a denser crumb.
Because flour is usually described by type rather than by measured protein, this difference is often invisible until the dough is mixed.
Altitude changes the oven stage
At higher elevations, lower air pressure allows gas in the dough to expand more and water to evaporate at a lower temperature.
Loaves rise faster and can overshoot before the crumb sets, while the surface dries sooner than it would at sea level.
Adjustments for altitude typically involve shortening fermentation and raising hydration, which addresses both effects at once.