A few random observations from the first days here....
1. The emergency vehicles drive with their flashing lights on. I haven't figured out yet how people know if they are getting pulled over.
2. Throughout the day you can see people wearing anything from tank tops to turtlenecks. Throughout the year, the temperature in Mexico City ranges from about 50-80 degrees F. The weather changes quite a bit throughout the day. It's somewhat chilly in the mornings and evenings, but gets warm in the afternoon, especially in the sun. Rain at any point in the day can obviously affect the temp. Walking down the street in the middle of the day, I've seen people in heavy sweaters walking next to people in tank tops.
3. There are lots of chains here. So far I've seen: Starbucks, Walmart, Office Depot, McDonalds, Burger King, 7 Eleven, Papa Johns Pizza. According to the taxi driver tonight there's also a Six Flags!
4. Close-toed shoes. Almost everyone wears close-toed shoes -- lots of boots and sneakers (including Converse). While there are a few sandals and open-toed shoes, I have a feeling mine won't be getting much use for a while!
5. When it rains, it pours! I know I mentioned it earlier, but it's worth mentioning again. It's rainy season now, so lots of rain -- not as bad as I expected though. So far it's been pretty sunny during the day, with rain in the later afternoon or evening. Today we got caught in it and were a little damp for dinner.