Here is a run down of some alternative ones you can check so that your picnic in silver lake doesn't get rained on. Here are some sources of weather information about Shenzhen:
This might be the most accurate site but we just found it and most of the information is in Chinese but of course you can understand the temperature in Celsius.
According to this site if you want the Weather forecast by phone you can also call 12121.
Weather Underground also has a nice feature where if you have a calendar program like Apple's iCal, you can subscribe to a calendar feed of the weather and display the forecast directly in your calendar. Just copy the URL below. http://www.wunderground.com/auto/ical/global/stations/59493.ics?units=both
If you have better ways of getting the weather forecast or know of some other sites, please post a comment here.
Follow Typhoons as they approache Shenzhen and prepare for strong winds and rain.
National website for following typhoons in China