Project 22: Astro-Weather Forecasting vs. Meteorological Data
Book: The Big Astrology Book of Research by Renay Oshop
Source: bigastrologybook.com
🌟 Overview — What We Asked
Do planetary positions — particularly placement in astrological elements (Fire, Earth, Air, Water) — correlate with measurable changes in daily precipitation and temperature across the global historical weather record? Does the ancient claim "Water signs bring rain" survive scrutiny?
💡 Why This Matters
Weather prediction is one of astrology's oldest claimed practical applications. Ancient agricultural calendars were partly astrological; folk traditions in many cultures link lunar phases and planetary positions to planting conditions. With 129,562 NOAA stations spanning 124 years, this is the most comprehensive possible test: if any systematic planetary weather correlation exists, this dataset will find it.
📊 The Data
| Source | Description |
|---|---|
| NOAA GHCN-Daily | Global Historical Climatology Network; 129,562 station files; daily PRCP and TMAX; 1900–2024 |
| Swiss Ephemeris | Planetary positions for all 12 bodies in both Tropical and Vedic (Lahiri) zodiacs, every day 1900–2024 |
Both data sources are genuine. NOAA GHCN-Daily is the premier publicly available long-term daily weather dataset. A pre-computed planetary lookup table (astro_weather_features.csv) was generated using the Swiss Ephemeris, recording daily sign and element for each body.
📈 Results
1. The "Water Sign" Hypothesis: Seasonal Artifact
| Sun Element (Tropical) | Mean Precipitation (tenths mm) |
|---|---|
| Fire | 23.05 |
| Earth | 23.31 |
| Air | 23.40 |
| Water | 23.45 |
The Water sign bias exists — but it's tiny: +1.7% above average, with near-zero practical significance.
⚠️ The Critical Confound
The stronger Water sign / precipitation correlation found in pilot analysis (+14%) was a regional seasonal artifact.
The Sun moves through Cancer (June–July) during Northern Hemisphere summer monsoon season, through Scorpio (October–November) during Northern Hemisphere autumn rains, and through Pisces (February–March) during late-winter precipitation in many climates. Any correlation between "Sun in Water signs" and increased precipitation in a Northern-Hemisphere-dominated dataset is tracking seasonality — the calendar, not astrology.
Hemisphere split confirms it:
| Hemisphere | Wettest Sign Element |
|---|---|
| Northern (104,205 stations) | Differences negligible — fractions of a percent |
| Southern (25,357 stations) | Air/Water wetter, Fire/Earth drier — reversed from Northern |
In the Southern Hemisphere, Water and Air sign periods are wetter — because June–August (Fire signs) is the Southern winter/dry season, while October–March (Air/Water signs) is the Southern summer/wet season. Both hemispheres track their own seasonal calendars.
Conclusion: The Tropical Zodiac functions as a calendar. Different regions have different rain calendars. When the dataset is dominated by any geographic region, zodiacal correlations emerge — but they track climate, not planetary influence.
2. Moon Sign: Consistent Null
| Hemisphere | Moon in Water | Moon in Fire | Difference |
|---|---|---|---|
| Northern | 23.43 | 23.35 | +0.4% |
| Southern | 22.10 | 22.02 | +0.4% |
The Moon moves through all 12 signs every 27.3 days. It shows no consistent precipitation variation by sign in either hemisphere.
3. Slow Planets: Climate-Epoch Proxies
The full element analysis found the Neptune Tropical result strikingly large (+0.899 mean PRCP difference). But Neptune moves ~1° per year, spending ~14 years in each sign. Its "sign" at any given time is nearly identical to its sign a year earlier — and to the sign 14 years ago. Neptune-in-Water is a multi-decade climate epoch marker, not a causal variable. The correlation tracks decadal climate patterns (El Niño cycles, Atlantic Multidecadal Oscillation) that happen to coincide with Neptune's extremely slow sign transitions.
This is the "Slow Planet as Climate Proxy" pattern: outer planets serve as demographic/climate-epoch tags, not astrological signals.
4. Tithi Analysis — One Potentially Non-Trivial Signal
The Tithi analysis (30 lunar day bins based on Moon–Sun angular separation) revealed a persistent pattern:
| Lunar Phase | Approximate PRCP (tenths mm) |
|---|---|
| Waxing Quarter (Tithi 8–9) | ~46.0 (highest) |
| Waning Quarter (Tithi 23–24) | ~45.5 |
| New Moon (Tithi 1) | ~41.5 |
| Full Moon (Tithi 16) | ~40.9 |
Precipitation dips ~11% during New Moon and Full Moon (syzygy) periods compared to Quarter Moon phases. This pattern is physically plausible: at syzygy (Sun, Moon, Earth aligned), tidal forces are maximized, which may affect atmospheric circulation. Notably, this contradicts the folk belief that Full Moons bring storms — it suggests they may actually correlate with slightly drier conditions.
This is the one potentially non-trivial signal in the dataset. It requires replication and mechanism investigation before interpretation.
🔍 What the Numbers Mean
Fast planets (Sun, Moon, Mercury, Venus, Mars) cycle through all signs frequently and correlate with precipitation primarily through seasonal timing. Their "element" is effectively a calendar proxy.
Slow planets (Jupiter through Pluto) spend years in a sign and act as climate-epoch markers — tagging multi-year climate patterns they coincide with by chance of slow motion.
The question "do Water signs bring rain?" dissolves on inspection: the Tropical Zodiac is a calendar, and different parts of the calendar are wetter or drier depending on geography. There is no evidence of a planetary mechanism beyond this.
⚠️ Statistical Caveats
- Multiple testing: 12 bodies × 2 zodiacs × 4 elements × 2 weather variables = hundreds of comparisons. No results should be treated as confirmed without preregistered replication.
- Seasonal confounding is the primary concern for all Sun-based correlations.
- Station coverage is uneven globally — Northern Hemisphere is overrepresented.
- Effect sizes are tiny: even the largest effects are fractions of a percent of mean precipitation, with no practical meteorological significance.
🌟 Conclusion
After analyzing 124 years of daily precipitation data from 129,562 global weather stations:
- The "Water sign" precipitation effect is a seasonal confound — the Tropical Zodiac tracks the calendar, which tracks climate
- Moon sign placement has no detectable effect on daily precipitation
- Outer planet "element" correlations reflect multi-decade climate patterns, not planetary influence
- The Tithi syzygy suppression (New/Full Moon ~11% drier than Quarter phases) is the only consistent globally-replicated pattern — and it contradicts the folk belief about Full Moon weather
The data does not support traditional astro-meteorological claims.