Monthly Forecast

Monthly Forecast for May 2025

Hong Kong is expecting:

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

Additional information:

Affected by unsettled weather associated with the troughs of low pressure, the chance of having normal to above normal rainfall over southern China in the first to middle part of May 2025 is expected to be slightly higher.
Southwest monsoon is expected to prevail gradually over the coast of southern China in the middle to latter part of May 2025.

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.
Taking into consideration of the impacts of global warming and latest ENSO status, different climate model forecasts and other objective forecast guidance, the temperature of May 2025 in Hong Kong is expected to be normal to above-normal and the chance of normal to above-normal rainfall in the month will be slightly higher.

Note:

The Observatory gratefully acknowledges the European Centre for Medium-Range Weather Forecasts, 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 monthly forecast for Hong Kong.
Monthly Forecast for June 2025 will be available around 1st June 2025.
Monthly mean temperature and rainfall categorical forecasts charts.

Monthly 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)