April was cooler than usual due to the frequent passage of cold fronts, which brought the mean monthly temperature to 21 degrees Celsius, about 1.5 degrees below normal, the Hong Kong Observatory says.

The month was gloomy with only 49.2 hours of total bright sunshine, 52% below normal. It was also drier with 78.9mm of rain, 58% below normal, and bringing the accumulated rainfall since January 1 to 234.1mm, 31% below normal.

Due to a maritime airstream Hong Kong was mainly cloudy with coastal fog on the first day of the month. With a cold front passing the south China coastal areas the next morning the weather became cooler with some rain patches April 2 to 4.

The return of the maritime airstream brought foggy weather and a few light rain patches for the following two days. Visibility at Waglan Island fell to 100m on April 5.

The northeast monsoon brought cooler weather and rain to Hong Kong April 7 to 10 with a few squally thunderstorms on April 8. Dominated by a southerly airstream, the weather was warm and foggy April 11 to 13. The temperature rose to a maximum of 29.5 degrees on April 13, the highest of the month.

Affected by the strong northeast monsoon local weather was cloudy with rain April 14 to 18. It was cool on April 15 and 16 with the minimum temperature falling to 13.5 degrees on April 15 - the month's lowest. Foggy weather returned on April 19 and persisted over the next two days.

A cold front brought occasional rain and a few squally thunderstorms on April 22. Associated gusts of about 100km an hour were recorded at Chek Lap Kok. The weather turned dry with some sunny periods over the next three days. Another cold front brought a few rain patches from April 26 to 28.

With light winds, visibility at Chek Lap Kok fell to below 1km on April 29. A broad rainband moving across the Pearl River Estuary brought thundery showers that afternoon. More than 50mm of rain was recorded over parts of the New Territories and Lantau Island. After its passage there were some sunny periods on the last day of the month.