El Nino / La Nina Rainfall Comparison

ENSO - El Niño / La Nina Information for Site 231

ENSO (El Niño Southern Oscillation) is the warming and cooling of the ocean water along the Equator in the Eastern Pacific Ocean near South America. The warm phase is called El Niño and the cold phase is called La Nina.

When the Eastern Pacific Ocean is 0.5 degrees Celsius above normal for 5 consecutive 3-month average periods, an El Niño is declared. When the Eastern Pacific Ocean is 0.5 degrees Celsius below normal for 5 consecutive 3-month average periods, a La Nina is declared.

The El Niño and La Nina are declared as Weak, Moderate, or Strong depending on how far from normal the water temperature gets. When the temperature is above 1.5 degrees Celsius, it is declared as strong. When the temperature is above 1.0 degrees Celsius, it is declared as Moderate. When the temperature is above 0.5 degrees Celsius, it is declared as Weak.

The effect on Ventura County trends to be wetter with El Niños and drier with La Ninas. Although the top driest years have been Neutral or Weak or Moderate El Niños.

Data for calculating ENSO Index (ONI) is provided by the Climate Prediction Center.


Strongest El Niños

#Water
Year
IntensitySiteSeason
Total
Percent
Normal
12016+2.5 - N/AN/A
21998+2.3231 - El Rio-County Yard40.59269.3%
31983+2.1231 - El Rio-County Yard30.24200.7%
41973+2.0231 - El Rio-County Yard19.03126.3%
51958+1.7231 - El Rio-County YardN/AN/A
61992+1.6231 - El Rio-County Yard19.47129.2%
71966+1.5231 - El Rio-County YardN/AN/A

Top 10 Wettest Years

#Water
Year
SiteENSO StateIntensitySeason
Total
Percent
Normal
11998231 - El Rio-County YardStrong El Niño+2.340.59269.3%
21978231 - El Rio-County YardWeak El Niño+0.833.36221.4%
32005231 - El Rio-County YardWeak El Niño+0.731.77210.8%
41983231 - El Rio-County YardStrong El Niño+2.130.24200.7%
51995231 - El Rio-County YardModerate El Niño+1.030.12199.9%
61980231 - El Rio-County YardWeak El Niño+0.628.28187.7%
71993231 - El Rio-County YardNeutral+0.326.26174.3%
81986231 - El Rio-County YardNeutral-0.422.29147.9%
91969231 - El Rio-County YardModerate El Niño+1.021.59143.3%
101979231 - El Rio-County YardNeutral+0.119.92132.2%

Strongest La Ninas

#Water
Year
IntensitySiteSeason
Total
Percent
Normal
11974-1.9231 - El Rio-County Yard13.4289.1%
21989-1.8231 - El Rio-County Yard7.7351.3%
31976-1.6231 - El Rio-County Yard12.6283.7%
42000-1.6231 - El Rio-County Yard15.98106.0%

Top 10 Driest Years

#Water
Year
SiteENSO StateIntensitySeason
Total
Percent
Normal
11990231 - El Rio-County YardNeutral+0.15.0133.2%
22007231A - El Rio - RiverparkModerate El Niño+1.06.1640.9%
32002231 - El Rio-County YardNeutral-0.26.3542.1%
41987231 - El Rio-County YardModerate El Niño+1.27.0546.8%
51989231 - El Rio-County YardStrong La Nina-1.87.7351.3%
61972231 - El Rio-County YardWeak La Nina-0.87.7951.7%
71977231 - El Rio-County YardWeak El Niño+0.89.0359.9%
82004231 - El Rio-County YardNeutral+0.39.1760.8%
91984231 - El Rio-County YardNeutral-0.59.9265.8%
101999231 - El Rio-County YardModerate La Nina-1.49.9365.9%