Climate Comparisons and Weather Patterns Due to El Nino

ClimateComparisons and Weather Patterns Due to El Nino

ClimateComparisons and Weather Patterns Due to ElNino

ElNino is the warm phase of the El Nino Southern Oscillation (ENSO),which is a cycle of cold and warm temperatures that develop in theocean water situated around east-central and central Pacific El Ninois accompanied by high atmospheric pressure in the Western Pacificand low pressure in the Eastern Pacific (Hong, 2016). Inherently, ElNino cause changes in the microclimates of the regions that lay tothe west and east of the pacific particularly, it tends to bringrain while La Nina (the cool phase of ENSO) stops it (Hong, 2016).This paper analyzes climatic data that demonstrates the effects of ElNino event, which lasted between October 2015 and September 2016, onthe precipitation rates and patterns of Chico, California.


Chico,California experiences Mediterranean climate it has dry hot summersand mild winters. Temperatures can rise up to or even beyond 1000F(38 degrees Celsius) during summer. Nevertheless, Chico has mild wetwinters with most rainfall being experienced in January this monthis also the hottest throughout the year, with average hightemperatures of up to 94 degrees Fahrenheit, and an average low of 61degrees Fahrenheit. As a result, Chico, like other parts ofCalifornia, usually experiences a multi-year drought. TheMediterranean climate of Chico is illustrated in the climograph inFigure 1 below.

Figure1: Climograph for Chico, CA

Effectof El Nino on California’s Winter Precipitation

Inthe event of a strong El Nino event, winter in California ischaracterized by an increase in the number of precipitation days(this is seen in figure 2). In fact, El Nino reinforces the mild, wetsummers increasing the amount of precipitation way above averagethis is shown (figure 2). Inherently, this is essential for reversingthe drought that arises during the hot Mediterranean summers of theregion.

Effectof Latest El Nino on Chico’s Precipitation

Overthe years, El Nino has had an upgrading effect on the precipitationof Chico the region’s precipitation pattern and average aredemonstrated in figure 3. Between October 2015 and September 2016,Chico experienced a strong El Nino event from past records, El Ninoincreases the precipitation of Chico, CA significantly this is seenin figure 3 below. However, the average precipitation for betweenOctober and September was barely above the state’s long-termaverage (this is illustrated in figure 2 below). In fact, it was waybelow average when compared to the El Ninos of 1982-83 and 1997-98these were marked by more than 40 days of precipitation, whereas thelatest El Nino had less than 40 precipitation days, as shown infigure 2 below.

Figure2: El Nino Impact on Winter Rain Days. Source:

Figure2: California Precipitation and ESNO Status, Dec-Mar. Source:


Althoughthe El Nino event has been essential for mitigating the multi-yeardroughts that strike Chico every year due to its unique Mediterraneanclimate, the precipitation between the El Nino event that occurredbetween October 2015 and September 2016 barely reached the state’saverage. In such a manner, the effects of the effects of droughts inChico were not reversed as had been expected. Correspondingly,although the October 2015-September 2016 was marked by one of thestrongest El Nino events on record, the rate of precipitation inChico, California was below average.


Hong,L.-C. (2016).&nbspSuperEl Niño.Singapore: Springer.