This is not only my hypothesis. Modern research confirms that birth season correlates with human temperament at a statistically significant level. The papers are not difficult to find; researchers are taking this question seriously.
But I believe these studies stop at the surface.
What truly matters is not the season itself, but the climate variables hidden within the season. The season is a coarse container. What it holds — temperature, light duration, rate of temperature change — are the actual physical variables at work. It is these variables, not the label ‘spring’ or ‘winter,’ that matter.
Which variables are decisive? What is the relative weight of each? I conducted a systematic calculation and analysis.
Method
This is not a rigorous scientific derivation. It is a fuzzy but logically coherent quantitative reasoning.
My starting point was a hypothesis: if the 12-zodiac and 24-solar-term classification systems are valid, then dividing the year into 12 segments should produce segments with climate signatures that are consistently identifiable in the data.
Based on this, I collected daily climate data spanning several decades from the regions where both systems originated: the Yellow River basin of China, ancient Babylon (central Iraq today), Alexandria, and Athens.
I then trained a nonlinear classifier on this data: given the climate readings for a specific day, can the model correctly identify which of the 12 segments it belongs to?
Accounting for year-to-year climate variation, I set a baseline: if classification accuracy holds above 80%, it would confirm a genuine correspondence between climate data and the 12-segment structure.
The results exceeded that baseline：91%.
Key Finding: The Weight of Temperature
More valuable than the accuracy score were the variable weights the classifier returned.
Temperature and rate of temperature change together account for approximately 0.84 of the total weight.
This number is broadly consistent with intuition — we all know that the feeling of a season is primarily about warmth and cold — but now it is quantified rather than merely felt. Light duration and other climate variables carry the remaining weight, and are not negligible, but temperature is the dominant variable.
From Time Labels to Climate Parameters
There is a critical shift here that deserves its own explanation.
The traditional zodiac system uses birth date to determine a person’s sign. This is a time label — essentially a crude proxy variable. In the era when these systems originated, date was the most convenient tool available for tracking climate rhythms.
But the relationship between date and climate shifts with latitude, year, and region.
My method makes a substitution: replace the date with actual climate parameters, directly calculate the climate characteristics corresponding to a birth location and time, and map the result onto the 12-segment framework.
This changes the output from ‘you were born on this date’ to ‘this is what the world looked like when you were born.’
A Concrete Example
Birth date: April 11, 2002. Location: Berlin (52°31’N, 13°24’E).
Traditional zodiac: Aries (by date).
Climate-based output:
Pisces: 60.89%
Aries: 38.61%
Berlin sits at approximately 52°N — about 15 degrees north of the Mediterranean regions where the zodiac system originated. When Athens and the Yellow River basin have already passed the Spring Equinox, with temperatures rising sharply and life surging forward, Berlin in early April is still closer to late winter: colder, dimmer, spring arriving later.
So the climate signature of April 11 in Berlin more closely resembles the conditions the Pisces segment was built to describe — not Aries.
This output is a more honest account of what the world looked like on the day you were born than a fixed date boundary ever could be.