El Niño / La Niña Local Effect on Temperature

Temperature data was broken up by month and by event, based on the locally derived El Niño/La Niña yearly anomalies, for four stations in west central and southwest Florida: Tampa, Lakeland, Sarasota-Bradenton, and Fort Myers. Average temperatures are linked below:

Tampa Average Temperature by Category Lakeland Average Temperature by Category Sarasota-Bradenton Average Temperature by Category Fort Myers Average Temperature by Category

The results show that: Strong El Niño events, temperatures were above average in December then below average for January through April. Weak El Niño events, temperatures were genearlly slightly below average December through April. Weak La Niña events, temperatures were slightly below average in December then near to slightly above average for January through April. Strong La Niña events, temperatures were generally slightly above average December through April.

To get a better picture, the anomalies were separated into high temperature anomalies and low temperature anomalies. These graphs are linked below.

Tampa Temperature Anomalies During Strong El Niño Events Lakeland Temperature Anomalies During Strong El Niño Events Sarasota-Bradenton Temperature Anomalies During Strong El Niño Events Fort Myers Temperature Anomalies During Strong El Niño Events

These charts show that the high temperatures skew the average temperature. The high temperatures are much farther below normal than the low temperatures during strong El Niño years. This result indicates significant cloudiness is present, keeping daytime temperatures low while preventing overnight temperatures from becoming too cold. In fact, Tampa has on average 34 percent more cloud cover during strong El Niño events than during strong La Niña events. The additional cloudiness is likely due to a combination of more storms affecting the area as well as a stronger jet stream carrying high clouds across the area from the Pacific Ocean.

Temperature anomalies during strong La Niña years are linked below:

Tampa Temperature Anomalies During Strong El Niña Events Lakeland Temperature Anomalies During Strong El Niña Events Sarasota-Bradenton Temperature Anomalies During Strong El Niña Events Fort Myers Temperature Anomalies During Strong El Niña Events

These graphs show the opposite tendencies of strong El Niño years: i.e. high temperatures are more above normal than low temperatures. This indicates much less cloudiness during strong La Niña years, allowing for significant solar warming during the day and radiational cooling at night.