Seasonal Forecast

Seasonal Forecast for May-July 2024

Hong Kong is expecting:

1.	normal to above-normal temperature
2.	normal to below-normal rainfall

Assessment (as of 29 April 2024):

In the past month or so, the weakening trend of the El Niño continued although sea surface temperatures over the central and eastern equatorial Pacific were still warmer than normal. Based on the latest oceanic observations as well as forecasts by a number of climate models around the world, the El Niño is expected to continue to weaken, transitioning to the ENSO-neutral state by end of spring this year. Subsequently, the sea surface temperatures in the concerned region are expected to continue to decrease, indicating a likelihood of La Niña development starting in the latter half of 2024.
Against the backdrop of climate warming, May-July temperatures in Hong Kong exhibit a significant long-term increasing trend. The chance of normal to above-normal temperature is generally higher. Besides, the majority of climate models around the world forecast normal to above-normal temperature over southern China for May-July 2024. Hence, the temperature of May-July 2024 in Hong Kong is expected to be normal to above normal.
Taking into consideration objective guidance and statistical analyses of past performance of climate models and the transition from the El Niño to the ENSO-neutral state and its impact on May-July 2024 rainfall in Hong Kong, the chance of normal to below-normal rainfall in Hong Kong for May-July 2024 is expected to be slightly higher. However, Hong Kong may still be affected by heavy rain. Members of the public are reminded to be prepared for the rain season.

Note:

Climate prediction centres around the world generate seasonal forecasts, employing a variety of methods including dynamical models, statistical methods, expert judgment and combinations of them. Predictions from different centres do not always agree and large discrepancies can occur at times. To formulate seasonal forecasts for Hong Kong, the Observaory takes into consideration available products from major climate prediction centres, past performance of climate models, and impacts of El Niño/La Niña, etc.
The Observatory gratefully acknowledges the Tokyo Climate Center of the Japan Meteorological Agency and the National Centers for Environmental Prediction of National Oceanic and Atmospheric Administration, USA for providing dynamical prediction model forecast and hindcast data to support the formulation of seasonal forecast for Hong Kong.
Seasonal Forecast for Summer (June-August) 2024 will be available around 1st June 2024.

Seasonal forecast charts provided by major climate centres:

For further information on this webpage, please contact Mr. W P Tse (tel:2926 8012, email:wptse@hko.gov.hk)