Seasonal Forecast

Seasonal Forecast for October-December 2023

Hong Kong is expecting:

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

Assessment (as of 29 September 2023):

Sea surface temperatures of the central and eastern equatorial Pacific remained above normal in the last five months and the sum of sea surface temperature anomalies exceeded 4.0℃. An El Niño event has been established. 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 persist in this autumn and winter 2023/24.
Against the backdrop of climate warming, October-December 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 October-December 2023. Hence, the temperature of October-December 2023 in Hong Kong is expected to be normal to above normal.
The impact of El Niño on October-December rainfall in Hong Kong is not significant. Climate models around the world generally forecast a higher chance of normal to above-normal rainfall over the coast of southern China for October-December 2023. Hence, the rainfall forecast of October-December 2023 in Hong Kong is expected to be normal to above normal.

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 November 2023-January 2024 will be available around 1st November 2023.

Seasonal forecast charts provided by major climate centres:

For further information on this webpage, please contact Mr. W P Tse (tel:2926 3114, email:wptse@hko.gov.hk)