March is the end of the winter and the beginning of Spring in Hong Kong so the weather turns towards the damp. Long periods of drizzle add to the cold weather and make this not such a good month for outside activities. However you will also find days of “winter” weather, left over from February where the sky is clear, the sun bright and it is all very nice.
Temperatures in March vary from 17C (62F) to 20C (70F) with some sunny days. During most of the month misty weather is common. Though Hong Kong people might call it “foggy” by the standards of places like London or San Francisco it really only counts as “mist”.
Even this mist is enough to cause the shipping traffic to all slow down and on bad days a ferry trip to one of the outlying islands could be delayed. There is no hope of getting a good view of Victoria Harbour from the Peak Tower on days like that!
Periods of 3 to five days of misty weather can alternate with clearer and drier weather.
Generally, the weather in March in Hong Kong improves a lot towards the end of the month. You will find that around the Easter Holiday the weather is often very good. I can remember visiting many Easter fairs in bright sunshine and wearing just a t-shirt and shorts.
If you are coming in March — say for Easter time — it will probably be fine.
Hong Kong Convention and Exhibition Centre (the flying saucer at the centre of the picture) disappeared behind the Spring mist in March in Hong Kong.
Although ICC wasn’t covered by the mist, you won’t be able to see much from the viewing deck in this sort of misty March weather.