The island is safe all times of the day in the populated areas, locals usually leave their houses and car unlocked. There are no poisonous or dangerous animals/insects on the island.
The most likely danger is large waves at cliffs and coastal waters during the monsoonOctober - February.
There are occasional sighting of reef and hammerhead sharks off the coast near the 'drop offs' underwater coastal shelf which drops off into the ocean depths, usually 5 - 30 meters offshore , however there have been no reported sharks attacks on Christmas Island in recorded history.
Some 4 Wheel Drive tracks are steep and slippery during the wet season, caution is advised when driving in national parks areas. Many tracks are 4 Wheel Drive only, in particular Dolly beach track and Dales and Blow Holes National Park areas. 4 Wheel driving experience required when venturing into these areas.
It is recommended that you bring a local or get local advice before heading off to any unpopulated national park areas.
Wear loose fitting clothing suitable for humid tropical climates. A hat and sunscreen is recommended if you're intending to be under the sun at the beach or fishing.
Bring water with you, as in humid environments you will tend to perspire more than normal.
Mosquito repellent should be brought on trips to rain forest areas, no instances of Malaria have ever been reported in recent history.
There are rare occurrences of Hepatitis A & B. However there is no particular vaccination required when visiting the island.