Correspondences
What is linked, what is not
Each arc joins two phenomena tested on this site. Green and animated: clear link (correlation significant at 5 % after correcting for autocorrelation, or a response outside chance in an event study). Grey: inconclusive test. A statistical link alone does not establish causation.
- Clear link
- Inconclusive
Hypotheses tested
28
Clear links
21
Causation demonstrated
0
Arc width from |r| of the stored result; several tests between the same phenomena are drawn as stacked arcs.
Hypothesis tested: During El Niño, convection leaves the western Pacific: eastern Australia receives less rain, mostly in the austral winter and spring; La Niña does the opposite (Risbey et al., 2009).
Spearman correlation ρ
-0.22
95% interval [-0.43; 0.05] (block bootstrap)
Pearson correlation r (lag 0 year(s))
-0.22
at the strongest lag
Aligned points
64
effective n ≈ 63 (autocorrelation)
p-value
0.080
two-sided, Fisher z transform, effective n
Period analysed
1961 → 2024
computed on Oct 25, 2026 · engine v1.0
Aligned series (standard deviations, after preprocessing)
Show the data as a table
Correlation by lag (year(s))
Show the data as a table
Method and sources
Niño 3.4 (NOAA PSL), June–November mean; Sydney rainfall (GHCN-Daily), June–November total, months kept when at least 90 % complete. Lag fixed at zero; Pearson and Spearman, 3-year block bootstrap on Spearman.
Computation parameters
{
"x": "mean Niño 3.4 of June–November (NOAA PSL)",
"y": "June–November rainfall total at Sydney (GHCN-Daily, months ≥ 90 % complete, totals scaled to the month)",
"lag": "fixed at 0",
"bootstrap": {
"seed": 20261023,
"block": 3,
"draws": 1000,
"statistic": "spearman"
}
}Inputs : psl.nino34.anom.monthly (945 pts, run #42) · ghcn.sydney.precip.daily (23,996 pts, run #3700)
Reading this result
The expected sign is there (less rain during El Niño), but the link is weak at Sydney: a coastal city also receives rain from the Tasman Sea, little related to ENSO. The El Niño signal is much clearer inland in Queensland and New South Wales; a non-significant result here does not contradict the literature. Correlation is not causation: common factors (seasons, cycles, trends) or coincidence can produce it. The p-values account for autocorrelation (effective n) but not for preprocessing choices; the confidence interval comes from a block bootstrap. The limits of the source data apply.
SOURCES OF THIS PAGE
- Niño 3.4 SST anomaly (NOAA PSL, ERSSTv5)
-
NOAA PSL, Niño 3.4 index: monthly SST anomaly (5°N–5°S, 170°–120°W) from ERSSTv5, climatology 1991–2020.
· source page ↗
Licence : U.S. Government work, public domain · retrieved on Oct 23, 2026 · SHA-256 879cf3cb31d7… - GHCN-Daily stations of the reference places (NOAA NCEI)
-
Menne, M. J., Durre, I., Vose, R. S., Gleason, B. E. and Houston, T. G. (2012). An overview of the Global Historical Climatology Network-Daily database. J. Atmos. Oceanic Technol., 29, 897–910. Menne, M. J., et al. (2012). Global Historical Climatology Network - Daily (GHCN-Daily), Version 3. NOAA NCEI.
· doi:10.7289/V5D21VHZ · source page ↗
Licence : U.S. Government work, public domain (data from national services under WMO Resolution 40); cite Menne et al. (2012) · retrieved on Oct 25, 2026 · SHA-256 fb525098ce40… - Risbey et al. (2009)
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Risbey, J. S., Pook, M. J., McIntosh, P. C., Wheeler, M. C., & Hendon, H. H. (2009). On the remote drivers of rainfall variability in Australia. Monthly Weather Review, 137(10), 3233–3253.
· doi:10.1175/2009MWR2861.1
Licence : Published literature; cited