Hi, January is a good time to visit, in fact Singapore can be visited year round. I have come across a wonerful post about Singapore on Tripoto, I'm attaching the same with this comment, you can go through it and plan your trip.
Jan is a good time to visit Singapore. Sg has tropical climate and usually pleasant to visit through the years except the monsoons. A 5 day trip would be sufficient to cover all the major tourist attractions.
Singapore is usually a go-anytime-of-the-year kind of place. It usually takes 5 full days to cover entire Singapore. I've put down a sample itinerary you can follow: Day 1 - Arrival In Singapore
Check in at the hotel, relax and take a walk to explore the new city. In the evening you can go for the amazing Night safari and enjoy the tram ride and animal show. Day 2 - City tour
After breakfast, proceed for half day city tour of Singapore. Visit one of the tallest hotels in the world, Swissotel-The Stamford, City Hall and Parliament House. Also visit
Mount Faber. Enjoy a drive through Orchard Road and make halt at photo stop on the Bay at the
Esplanade Theatres. From the waterfront, enjoy the sight of Merlion Singapore, the symbol and
business district of Singapore. Day 3 - Sentosa
After breakfast, head towards the famous Sentosa island. Board the cable car for a scenic drive to the island. Enjoy the luge and skyride. Sentosa offers many activities.
Go watch the dazzling wings of the time show to end the day. Day 4 - Universal Studios
Today after breakfast, go to Universal Studios Singapore where you can experience cutting–edge rides, shows and attractions based on your favourite movies and television series including the Ultimate 3D battle, Shrek 4-D Adventure, Revenge of the
Mummy, Madagascar: A Crate Adventure, Battlestar Galactica and many more! Day 5 - Take a tour on your own
Use Uber or Taxis or Public transportation (one of the best in the world) to roam around Singapore. Try out different dishes. Go to Singapore flyer - a giant wheel where you can actually get a glimpse of not just the entire city but a bit of Malaysia and Indonesia as well from the top! Try out the views from Marina Bay Sands hotel. Don't miss Gardens by the Bay, one of the most famous attractions in Singapore. You could also go to Arts and Science museum and Botanical Gardens if you are interested. Visit little India as well to see a different Singapore and shop at Mustafa market in the night. You find everything from a needle to a computer there :) Day 6 - Departure
Have a delicious breakfast and reach airport in the morning. Book an afternoon flight and spend some time in the airport as Singapore's Changi airport is a destination in itself! Go to the butterfly park inside the airport :)