ENSO Strengths

This table shows the forecast probability (%) of relative Niño-3.4 index exceeding a certain threshold (in degrees Celsius). For negative thresholds, the table shows the probability (%) of a relative Niño-3.4 index value that is less than (more negative) that value. For positive thresholds, the table shows the probability (%) of a relative Niño-3.4 index value that is greater than (more positive) that value. This tool supports the official ENSO Diagnostic discussion updated on the 2nd Thursday of each month.
Target	≤ -2.0°C	≤ -1.5°C	≤ -1.0°C	≤ -0.5°C	≥ 0.5°C	≥ 1.0°C	≥ 1.5°C	≥ 2.0°C
MAM	~0	~0	~0	1	~0	~0	~0	~0
AMJ	~0	~0	~0	~0	20	~0	~0	~0
MJJ	~0	~0	~0	~0	61	5	~0	~0
JJA	~0	~0	~0	~0	79	26	2	~0
JAS	~0	~0	~0	~0	87	49	12	1
ASO	~0	~0	~0	~0	90	63	27	6
SON	~0	~0	~0	~0	92	72	41	15
OND	~0	~0	~0	~0	93	77	50	23
NDJ	~0	~0	~0	~0	92	77	51	25
	≤ -2.0°C	≤ -1.5°C	≤ -1.0°C	≤ -0.5°C	≥ 0.5°C	≥ 1.0°C	≥ 1.5°C	≥ 2.0°C
The values are based on the analysis published in: L'Heureux, M. L., M. K. Tippett, K. Takahashi, A. G. Barnston, E. J. Becker, G. D. Bell, T. E. Di Liberto, J. Gottschalck, M. S. Halpert, Z.-Z. Hu, N. C. Johnson, Y. Xue, and W. Wang, 2019: Strength Outlooks for the El Niño-Southern Oscillation. Wea. Forecasting, 34, 165-175, https://doi.org/10.1175/WAF-D-18-0126.1.