Hi Pamela,
Many thanks for your message.
It is usually mild in Malta during the winter, with plenty of sunshine too, with daytime temperatures usually 15ºC (59ºF) or above and sometimes also around 20ºC (68ºF). It can get chilly in the evening though, and most rainfall tends to occur in the winter months, although the average rainfall is still low. I would recommend a light raincoat, lightweight tops for the daytime, with some warmer sweaters for evenings.
The Christmas and New Year dinners are not formal, and the dress tends to be smart/casual. Above all, i'd wear something you're comfortable in.
I hope this helps,
Merry Christmas and a happy new year, have a wonderful trip.
Warm regards,
Cheryl, your editor