The temperature of external air is now reduced 10-15 degrees from the normal 25-34 degrees and humidity reduced as well, there are resulted in the clean room humidity less than the spec value. The weather this does not happen often. Anticipated date during 25- 27 Jan, 2016 (according to the meteorological department). When the external air temperature and humidity into the normal state would cause the humidity in clean room according to the spec value.