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Monthly Forecast

Monthly Forecast for May 2026


Hong Kong is expecting:
1.
 normal to above-normal temperature
2.
 normal to above-normal rainfall



Additional information:
  1. Troughs of low pressure are expected to bring unsettled weather to southern China in the first week of May 2026. The chance of having normal to above-normal rainfall over the region will be slightly higher in the month.
  2. The subtropical ridge is expected to cover the coast of southern China in the middle part of May, temperatures over the region are expected to be normal to above-normal in the month.
  3. The southwest monsoon may prevail gradually over the central and southern parts of the South China Sea in the latter part of May 2026, favoring the development of low‑pressure systems over the region.

Assessment (as of 29 April 2026):
  1. In the past month or so, the sea surface temperatures of the central and eastern equatorial Pacific rose and remained 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 region are expected to be normal to above normal for the rest of spring 2026. With the continued warming trend in the region through autumn 2026, the situation is expected to develop into an El Niño event in the second half of this year.

  2. 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 2026 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 higher.


Note:
  1. 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.

  2. Monthly Forecast for June 2026 will be available around 1st June 2026.

  3. Monthly mean temperature and rainfall categorical forecasts charts.

  4. Ten days constitute a "ten-day period," and three such periods make up a month. The first ten days of each month are called “the first part of the month”, the second ten days are “the middle part of the month”, and the remaining days are referred to as “the latter part of the month”.

 
Monthly forecast charts provided by major climate centres:
Related links:
| Seasonal forecast | Annual outlook | El Niño and La Niña | Climate change |
For further information on this webpage, please contact Mr. W P Tse (tel:2926 8012, email:wptse@hko.gov.hk)