It was found that Thon Buri district had the highest PM2.5 daily average at 67.91 micrograms, while the PM2.5 level in Pathumwan district stood at 56.79 micrograms and Wang Thonglang district recorded 55.06 micrograms. Meanwhile, the international air-pollution monitoring websitehttp://aqicn.org/ revealed on Monday that as of 1pm, the hourly PM2.5 level in Bangkok had reached the unhealthy level of 154. Therefore, the PCD issued an alert for people with health vulnerabilities in Bangkok to avoid outdoor activities and stay indoors. As on the effort to relieve air pollution in Bangkok, Royal Rainmaking and Agricultural Aviation Department has started the first rainmaking flight on Monday in order to let the rain wash down the very fine particulate in the air. The rainmaking squadron will continue this mission until this weekend or until the air pollution situation is resolved.