We are in Western Australia...very hot today around 95f or 36c. Christmas here is usually hot, but as I am English and my husband Sicilian, we do the usual European Christmas (mix of English and Italian food). We have a huge late lunch which extends into the evening...our children, their partners and other extended family all gather under our patio and eat and drink. We are very fortunate to have a swimming pool, so everyone hops in if it gets too hot (the dogs included). We put up the usual decorations and have a large potted conifer (pine) that we bring in and decorate, we also have a nice nativity scene as that is traditional for my husband.
We open our gifts from under the tree now, but when the children lived at home (even when they got big), we used to put gift/sweet filled pillowcases at the end of their beds on Christmas Eve....then later in the morning, they got the tree gifts (usually bigger items).
This year we did a "Christmas in July"...(our winter). It is like a mini-Christmas (minus the majority of the decorations). We had traditional Christmas food, a little tree with just tinsel and lametta (long strands of tinsel stuff) and did a Secret Santa fun gift game instead of proper presents. It is becoming popular here - eating Christmas fare when it is so cold cold/wet is fun...also gives us another chance to get everyone together and eat too much!