I have worn mine in temperatures ranging from about -7 degrees Celsius to about 28 degrees celsius. It's not the best choice for headgear in either of your options. In very cold weather your ears will freeze and in extremely hot weather you will sweat like mad. You can of course remove the liner and sweatband, which will help a lot. Probably the best hat in hot temperatures is a panama hat like the one Belloq wears. Otherwise it is a year round hat for me. The Federation is the best cheap Indy hat on the market, the best Raiders hat would be an Adventurebilt Deluxe. Hatsdirect has two overseas shipping options, Airmail and EMS Courier. Airmail is supposed to 5-10 days, so that would probably be the best choice.