Climatic phenomena

This page contains the analysis of climatic phenomena in the world, with a specific focus on El Niño and La Niña.

The analyzed data come from: USDA (United States Department of Agriculture), NOAA (National Oceanic and Atmospheric Administration) and Met Office (UK's national weather service).

Content overview:

Event detected El Niño
latest data: March 2024

Global maps on drought and vegetation growth

The map on the left shows the status of the Percent Average Seasonal Greenness index, an indicator about the health and growth of vegetation.

A PASG value of 100% indicates that the current seasonal pattern is comparable to the historical average for that location. This would indicate that the conditions of the vegetation are normal. PASG values ​​below 100% indicate a below average trend that could be related to some form of vegetation stress (e.g. drought, floods, fires, hail damage or pest infestation). PASG values ​​higher than 100%, on the other hand, represent a situation of better-than-normal dvelopment of the vegetation compared the recent historical one.

The map on the right shows the trend of the standardized precipitation index (SPI) which measures the ongoing phenomena of drought and rainfall.
El Niño or La Niña events influence the manifestation of these phenomena.

Through the drop-down menu it is possible to select a geographic area to deepen the analysis on the climatic conditions in progress.

After selecting the area of ​​interest, the following maps will be displayed:

The first map shows the total rainfall recorded, with the corresponding amount in mm. The next one shows the temperature anomalies, intended as a variation compared to the historical average (degree Celsius). The last map analyzes the situation of the minimum and maximum temperature, always expressed in degree Celsius.

Source: National Oceanic and Atmospheric Administration

El Niño/La Niña event detection

The ONI index (Oceanic Niño Index) measures anomalies related to the ocean temperatures, allowing to detect the occurrence of El Niño or La Niña events.

  • Index value higher than + 0.5 ° C: El Niño event
  • Index value lower than - 0.5 ° C: La Niña event

Records of events:

Calendar of the effects of El Niño and La Niña in the world

The chart reports a summary of the effects usually caused by El Niño and La Niña.

Select a climatic event:

The chart shows the effects that El Nino and La Nina events usually have in different parts of the world. Those effects can be summarized in two phenomena: drought (in red) and excessive rainfall (in blue). In the vertical axis we have the geographical areas affected by these phenomena, while the horizontal axis shows the months of the year. For example, If we refer to La Niña, Argentina is highlighted in red for the month of April, which means that drought is expected there during that month. This information can be analyzed along with the crop calendar for agricultural products, to have an idea of the possible impact on crops.