Seasonal Forecast

Seasonal Forecast for September-November 2026

Hong Kong is expecting:

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

Assessment (as of 31 August 2026):

In the past month or so, the sea surface temperatures of the central and eastern equatorial Pacific continued to rise significantly and stayed above normal. Based on the latest oceanic observations as well as forecasts by a number of climate models around the world, the warming trend in the central and eastern equatorial Pacific is expected to continue. The situation is forecast to develop into an El Niño event in late summer and persist at least until spring next year. It is expected to strengthen into a very strong event and peak around November and December this year, with a chance of becoming the strongest El Niño event on record since 1950.
Under the backdrop of climate warming, September-November temperatures in Hong Kong exhibit a significant long-term increasing trend. The chance of normal to above-normal temperature is generally higher.
Taking into consideration of the latest ENSO status, different climate model forecasts and other objective forecast guidance, the temperature of September-November 2026 in Hong Kong is expected to be normal to above-normal, and the chance of normal to below-normal rainfall will be slightly higher.

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 October-December 2026 will be available around 1st October 2026.

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)