Seasonal Forecast

Seasonal Forecast for May-July 2025

Hong Kong is expecting:

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

Assessment (as of 30 April 2025):

In the past month or so, sea surface temperatures of the central and eastern equatorial Pacific were near normal on the whole. Based on the latest oceanic observations as well as forecasts by a number of climate models around the world, the sea surface temperatures of the central and eastern equatorial Pacific are expected to remain near normal for the rest of this spring and summer this year.
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.
Taking into consideration of the latest ENSO status, different climate model forecasts and other objective forecast guidance, the temperature of May-July 2025 in Hong Kong is expected to be normal to above-normal and the chance of normal to below-normal rainfall will be slightly higher. However, Hong Kong may still be affected by rainstorms and localized 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 June-August 2025 will be available around 1st June 2025.

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)