In books, it says December to March is the best time to visit Sri Lanka which is true as the humidity and temperature is mild (28 degrees highest to 21 degrees of Celsius lowest). 
Though it says it rains less in this period, we have observed this is changing along with global weather patterns. But technically December to March is the best time for Sri Lanka while July and August are also very good months.
April and May are the warmest months in Sri Lanka and the temperature could reach 35 degree of Celsius during day time and 28 degrees of Celsius in the night.
June, September and October are moderate months in temperature and ranges from minimum 25 degrees and maximum 30 degree of Celsius.
Talking about rains, it says May, June and October are rainy but this has largely now changed. So in our opinion Sri Lanka is a 12 months destination where you will find sunshine somewhere in the Island.
If you are traveling in the months of May, June, September and October you are likely to get better hotel rates as the occupancy levels drop hotels tends to throw in discounts..
The only International Airport at present is Bandaranayake International Airport (Also know as Colombo International Airport), is approximately 30 kms north of Colombo and connected to Colombo downtown by an express highway. It is a 1 hour drive approximately to Colombo downtown.
It is recommended and encouraged that you purchase a comprehensive travel insurance in your country before arriving in Sri Lanka.
All nationalities entering Sri Lanka requires a Travel Authorization which could be applied using the government website http://www.eta.gov.lk/slvisa/. Travel Authorization is initially granted for 30 days four tourist purpose but could be extended for two months when in Sri Lanka at the Department of Immigration and Emigration. Please apply for Travel Authorization online before arrival in Sri Lanka.
Sri Lankan Airlines, the national carrier who currently operates direct flights to London Heathrow and other Asian hubs such as Singapore, Tokyo and Middle eastern hubs such as Qatar, Abu Dhabi, Muscat, Dubai. Sri Lankan Airlines also fly direct to Melbourne while most of the Indian major airports are well connected with direct flights.
KLM flies directly from Amsterdam to Colombo during winter time. Most popular route to Sri Lanka is via middle eastern hubs such as Qatar, Dubai and Abu Dhabi and Muscat flown by Qatar Airways, Emirates, Etihad and Oman Air.
Privately hired vehicle with a chauffeur - Best and recommended way of transportation when travelling in Sri Lanka is hiring a chauffeur driven private car or van for the entire trip. Though Sri Lanka is a small Island, it requires 1 to 6 hours of driving from attraction to attraction or destination to destination. Having your own privately hired car/van with a driver eliminates the hassle of booking taxis. Especially when you go for sightseeing, you can simply leave your luggage in the vehicle when you have your own privately hired vehicle. If you are travelling with kids, it is needless to explain how convenient of having a vehicle and driver at your disposal.
We do not recommend self driving in Sri Lanka as adherence to rules and regulations seems to be neglected. This holiday, it is better experienced when you have a private chauffeur.
Taxis – Hiring a taxi from point A to B will be cheaper than having your own privately hired vehicle with a chauffeur but taxi drivers do not speak good English. As the taxi leaves after dropping you, you have no way of keeping your luggage while you explore.
Public transportation – Not so developed and not on time. Unless you are backpacking, we do not recommend this method. But it is fun to take a scenic train ride from Colombo to Kandy or Kandy to Ella or even taking a short bus ride to experience how locals travel.
Domestic flights – There are private operators of scheduled and chartered domestic flights in Sri Lanka. If you are with time constraints, we would recommend considering taking scheduled domestic flights especially to and from Trincomalee, Passikudah, Yala, Sigiriya and also from Kandy.
If you have a group and want to get to point A to B fast, chartered flight or helicopters will come in handy.
Sri Lanka’s official currency is Sri Lankan Rupees (LKR). You can easily exchange any major currency notes such as USD, GBP, AUD and Euros at the arrival lounge of Colombo International Airport from a banking counter. If you forget or miss to do it, go to any bank in Sri Lanka in any city for currency exchange. You need to produce your passport for currency exchange in the banks.
Visa and Master Credit cards are widely accepted in Hotels, Restaurants and shops. Make sure you contact your card issuing bank before arriving in Sri Lanka to enable the card to use in Sri Lanka. American Express and Dinners Club Cards are not widely accepted.
ATM machines which supports Visa, Mastercard, Sirrus, Maestro and Plus networks are widely distributed in main and small towns. These will enable you to draw Sri Lankan currency at ease.
At the arrival lounge of Colombo International Airport, purchase a pre-paid SIM card with data and voice facility either from Dialog or Mobitel, the two major mobile network operators in Sri Lanka.
Sri Lankan climate is tropical, with distinct dry and wet seasons in different regions due to elevation. Humidity is generally 80%, not as intense as Thailand or Singapore. Colombo and low-lying coastal regions have a temperature of 28-32ºC. In the hill country the temperature drops, Kandy averages 25ºC, Nuwara Eliya 16ºC with coolish nights. The sea maintains a comfortable average temperature of 28 ºC all year round.
Sun protection lotion, sun glasses, sneakers, slippers and casual/leisure clothing and of course a camera.
Sri Lanka uses round and square 3 pin wall sockets on 230 V. Power adopters are readily available to buy in Sri Lanka.
