With the HK monsoon for the last 2 weeks, I have been getting fairly cool weather with my shoot in parts of Hong Kong but that also brought with it, persistent rain on the island. There were occasions where I braved the light rain and shoot with my Nikon D90 entirely unsheltered and it just keeps shooting. I guess as long as its not asian downpours like those in Malaysia and Singapore, you should be fine.
But, weather wise, HK is now a mess. With capitalist idealism at its peak for China, no one really cares about their lungs and their childrens'. You only get to see a day or two of blue skies right after the monsoon wind. Well, thankfully, I don't stay there...