Whilst most National Parks can be visited year-round and still promise a high chance of spotting wildlife, the following parks are at their peak during December: Uda Walawe, Sinharaja, Bundala
Dolphins and whales (blue & sperm whales) can be spotted off the southern coast near Mirissa and north-west coast near Kalpitiya during December.
December top tip
Peak season is well underway. Avoid the key Christmas dates to benefit from cheaper flights and to dodge the hotel's high season surcharges. Having said that, how better to spend Christmas than on a Sri Lankan beach?!