Traveling in multiple weather zones

I'm getting ready to leave for a whirlwind trip this Friday where my itinerary will include a trip to Southern California, Arizona and Toronto, Canada.    According to the weather reports, when I leave Raleigh it will be 70 degrees and raining, then 80 degrees in Southern California and windy, then 83 degrees and clear in Arizona, then 28 degrees and snowing in Toronto, Canada.  

With this kind of travel, there are a few strategies I keep in mind:

1) Pack all the light items in the carry-on bag.  For my trip to Canada, I'm going to need my parka and my all weather terrain shoes, but I can always change in the restroom at the airport after I pass customs.  No need to lug all that snow gear onto the plane when it will do well in the cargo hold.  I can get by with a sweater or a light jacket on the plane and in the terminal until my bags come off the belt.   If I don't have room in the check-in luggage, then I can carry the parka, but I'd rather not if it's not needed. 

2) Always pack a pair of gloves and a collapsible hat in carry-on luggage.  Even if the weather is hot, I've found that a pair of gloves comes in handy in a variety of circumstances.  More importantly, though, when the weather is cold, there's nothing like having a nice pair of gloves to keep your hands warm.   A baseball cap or hat with a bill or brim helps shade the eyes in the heat and protects the face from the rain and snow.  Don't worry about making a fashion statement.  It's more important to protect yourself.

3) Sunscreen, chapstick, eye drops and bottled water.  Hydration, hydration, hydration...no matter where you go, travel will dehydrate you in a number of ways.  All of these protect your body by keeping it hydrated and protected.  Fortunately, these are all items that are easily obtained when you travel, so you don't necessarily have to pack them, but if you want to save some money, then keeping these handy in your carry-on bags is a must. 

You can't always prepare for all things that will come your way, but I've found that these help in most travel situations.  Of course, traveling at off hours under less stressful conditions also helps to ease through these transitions as well. 

What steps do you take to prepare yourself when you're traveling between time zones and multiple climates? 

Do you have a "survival kit" that you use to help through the transitions?