4°C here in Zhengzhou, China, with slight breeze. But the big news is the air quality report, which is dismal - Air Quality Index of 242 (“very unhealthy”). Most of that is PM2.5 pollution from coal fires and construction — pretty typical for this part of China. It’s the biggest drawback to moving here from my previous, more rural location. Clear days are spectacular - blue skies and sunshine. But polluted days are nasty. Students tell me 242 is not bad. Last year, they said it topped 500.