El Niño and La Niña

El Niño and La Niña refer to the warming and cooling of surface waters over the central and eastern equatorial Pacific Ocean which affect the atmospheric circulation worldwide and regional climate in many parts of the world. Statistically, the influence of El Niño and La Niña on the climate of Hong Kong when compared to the ENSO-neutral state¹ can be summarized below:

El Niño

1. Generally wetter winter (Dec-Feb) and spring (Mar-May)
2. Unlikely to have tropical cyclones affecting Hong Kong before June.

La Niña

1. Generally cooler autumn (Sep-Nov) and winter;
2. Likely to have more tropical cyclones affecting the territory during August-October.

Further details are as follows:

1. What are El Niño, La Niña and ENSO?
   
2. Latest status
3. The impact of El Niño and La Niña on the climate of Hong Kong
4. Seasonal and annual rainfall charts
5. Blogs, videos
6. References

Note:

1. The ENSO-neutral state refers to the situation with neither an El Niño nor a La Niña in place.
2. El Niño or La Niña is not the sole factor for determining seasonal temperature and rainfall in Hong Kong. Please refer to this page for the latest seasonal forecast.