El Nino / La Nina Rainfall Comparison

ENSO - El Niño / La Nina Information for Site 101

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+2.5101A - Piru-Camulos Ranch8.3248.1%
21998+2.3101A - Piru-Camulos Ranch41.32239.1%
31983+2.1101A - Piru-Camulos Ranch38.84224.8%
41973+2.0101 - Piru-Camulos Ranch20.24117.1%
51958+1.7101 - Piru-Camulos Ranch30.88178.7%
61992+1.6101A - Piru-Camulos Ranch27.78160.8%
71966+1.5101 - Piru-Camulos Ranch22.42129.7%

Top 10 Wettest Years

#Water
Year
SiteENSO StateIntensitySeason
Total
Percent
Normal
12005101A - Piru-Camulos RanchWeak El Niño+0.743.53251.9%
21998101A - Piru-Camulos RanchStrong El Niño+2.341.32239.1%
31978101A - Piru-Camulos RanchWeak El Niño+0.839.00225.7%
41983101A - Piru-Camulos RanchStrong El Niño+2.138.84224.8%
51941101 - Piru-Camulos RanchN/AN/A36.35210.4%
61993101A - Piru-Camulos RanchNeutral+0.332.60188.7%
71969101 - Piru-Camulos RanchModerate El Niño+1.032.32187.0%
81952101 - Piru-Camulos RanchWeak El Niño+0.530.93179.0%
91958101 - Piru-Camulos RanchStrong El Niño+1.730.88178.7%
101995101A - Piru-Camulos RanchModerate El Niño+1.030.61177.1%

Strongest La Ninas

#Water
Year
IntensitySiteSeason
Total
Percent
Normal
11974-1.9101 - Piru-Camulos Ranch15.3088.5%
21989-1.8101A - Piru-Camulos Ranch10.6161.4%
31976-1.6101A - Piru-Camulos Ranch9.8557.0%
42000-1.6101A - Piru-Camulos Ranch14.1782.0%

Top 10 Driest Years

#Water
Year
SiteENSO StateIntensitySeason
Total
Percent
Normal
12007101A - Piru-Camulos RanchModerate El Niño+1.05.3230.8%
21961101 - Piru-Camulos RanchNeutral0.05.9834.6%
32002101A - Piru-Camulos RanchNeutral-0.26.2135.9%
42013101A - Piru-Camulos RanchNeutral-0.46.3336.6%
51990101A - Piru-Camulos RanchNeutral+0.16.6738.6%
62014101A - Piru-Camulos RanchNeutral-0.56.9340.1%
71987101A - Piru-Camulos RanchModerate El Niño+1.27.0340.7%
82018101A - Piru-Camulos RanchWeak La Nina-1.07.0740.9%
91948101 - Piru-Camulos RanchN/AN/A7.7745.0%
101951101 - Piru-Camulos RanchWeak La Nina-0.87.9946.2%