El Nino / La Nina Rainfall Comparison

ENSO - El Niño / La Nina Information for Site 036

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+2.5036A - Piru-County Fire Station9.3753.9%
21998+2.3036A - Piru-County Fire Station41.45238.4%
31983+2.1036A - Piru-County Fire Station40.36232.1%
41973+2.0036A - Piru-County Fire Station17.60101.2%
51958+1.7036 - Piru Citrus Assoc30.60176.0%
61992+1.6036A - Piru-County Fire Station26.03149.7%
71966+1.5036 - Piru Citrus Assoc21.86125.7%

Top 10 Wettest Years

#Water
Year
SiteENSO StateIntensitySeason
Total
Percent
Normal
11998036A - Piru-County Fire StationStrong El Niño+2.341.45238.4%
22005036A - Piru-County Fire StationWeak El Niño+0.740.86235.0%
31983036A - Piru-County Fire StationStrong El Niño+2.140.36232.1%
41941036 - Piru Citrus AssocN/AN/A38.57221.8%
51978036A - Piru-County Fire StationWeak El Niño+0.838.50221.4%
61969036A - Piru-County Fire StationModerate El Niño+1.032.75188.3%
71993036A - Piru-County Fire StationNeutral+0.332.72188.2%
81995036A - Piru-County Fire StationModerate El Niño+1.032.30185.7%
91952036 - Piru Citrus AssocWeak El Niño+0.531.64181.9%
101958036 - Piru Citrus AssocStrong El Niño+1.730.60176.0%

Strongest La Ninas

#Water
Year
IntensitySiteSeason
Total
Percent
Normal
11974-1.9036A - Piru-County Fire Station14.3082.2%
21989-1.8036A - Piru-County Fire Station10.5260.5%
31976-1.6036A - Piru-County Fire Station9.8456.6%
42000-1.6036A - Piru-County Fire Station12.8173.7%

Top 10 Driest Years

#Water
Year
SiteENSO StateIntensitySeason
Total
Percent
Normal
12007036A - Piru-County Fire StationModerate El Niño+1.05.7933.3%
21961036 - Piru Citrus AssocNeutral0.06.1735.5%
32002036A - Piru-County Fire StationNeutral-0.26.2836.1%
41990036A - Piru-County Fire StationNeutral+0.16.6038.0%
52014036A - Piru-County Fire StationNeutral-0.56.6538.2%
62013036A - Piru-County Fire StationNeutral-0.47.3142.0%
71987036A - Piru-County Fire StationModerate El Niño+1.27.4542.8%
82018036A - Piru-County Fire StationWeak La Nina-1.07.5943.6%
91948036 - Piru Citrus AssocN/AN/A8.0446.2%
101959036 - Piru Citrus AssocWeak El Niño+0.68.5449.1%