Comparing the traditional month-season associations with the astronomical definitions, we can see that:
Depending on which group you follow, here is how the seasons are verified for each half of the world: Meteorological Versus Astronomical Seasons | News months for the seasons verified
“Indigenous or traditional calendars are wrong.” Verification: ❌ False. Traditional ecological knowledge (e.g., Cree, Māori lunar calendars) is verified by local phenology. However, this article refers specifically to the Gregorian calendar system. Only the meteorological system does this
Early European cultures (Celtic, Norse) often defined seasons by lunar cycles or specific festivals (e.g., Samhain as Nov 1). These are not aligned with Earth’s axial tilt. If someone asks
False. Only the meteorological system does this. The astronomical system, which is what most schools teach, starts seasons on the equinox/solstice (around the 20th-22nd). Saying "Summer starts June 1st" is correct for meteorology but incorrect for astronomy.
If someone asks, "What months are summer?"—the answer depends on context: