[EvertonDiehard]

I noticed that night-time walks are hotter too. Morning walks are cooler as the routes (especially concrete pavements that cooled slower than grass) have been "cooled" through the night.

The air quality at night is also poorer than in the early morning. You are right about the heat escaping from the concrete walkways during my evening strolls. That plus the fumes from traffic are a real discouragement from going on long walks in SG. I enjoy my strolls in autumn and winter in temperate countries though. Nothing beats those evening walks after dinner.