The best time to visit Delhi is from October, when the city is refreshed after the monsoon, to early April. Expect a dry heat with very little humidity, though be aware that it can get chilly in the mornings and evenings during December, January and February (though the days remain generally warm and sunny). Temperatures begin to rise in March and April and by June can reach a stifling 45C. The monsoon arrives in July and continues until September.
Note: flight, boat, train and bus timetables change constantly, and airlines come and go, so please do not rely solely on this information for your travel planning. Check with relevant companies, or a flight search engine like Skyscanner, first.
The average flying time from London is 9 hours. From New York it's 16 hours, from Los Angeles 20 hours and from Sydney 14 hours.
From the UK:
British Airways, Air India and Virgin Atlantic fly from London Heathrow to Delhi. Cheaper fares are often available with the Middle Eastern airlines, including Emirates, Gulf Air, Qatar Airways and Kuwaiti Airlines, which fly from London Heathrow to Delhi via their respective hubs.
From the rest of Europe:
Air France, KLM, Lufthansa, Finnair, Alitalia and Swiss International Airlines fly to Delhi.
From Australia and New Zealand:
Various airlines, including Singapore Airlines, fly to Delhi via their respective hubs.
From North America:
Air India operates flights from New York (JFK and Newark), Chicago, Los Angeles, Montreal and Toronto to Delhi. You can also fly via London with one of the airlines mentioned above.
From Sri Lanka:
Sri Lankan Airlines has direct flights from Colombo to Delhi.
From within India:
You can fly direct to Delhi from most Indian cities - try Air India, Jet Airways, JetLite (formerly Air Sahara) and Kingfisher Airlines.
There are departure taxes of £40-£50. These are payable in advance along with your ticket - but are often excluded from your fare quote.
From the Airport:
Delhi Indira Gandhi International (25km from the city centre) is one of India's major air hubs. Most hotels in the city offer a transfer service; alternatively you can catch a taxi from the terminal - make sure you agree a price before you get in. The airport is also connected to the city centre by a safe, modern and efficient metro line - trains run every 12 minutes from 6am to 11pm.
Delhi has a safe and efficient metro system linking many sights within the city centre, as well as outlying suburbs. The metro network is rapidly expanding - route maps and fare information are available here.
India has a good rail network and Delhi is served by trains from most other Indian cities - check out Indian Rail for timetables or visit Seat 61 for a beginner's guide. There are 4 main railway stations - Old Delhi, Nizamuddin, Sarai Rohilla and New Delhi. First-class cabins sell out quickly so book in advance if you want more privacy than the flimsy second-class curtains offer. But both classes have air conditioning. Booking train tickets can sometimes be subject to a complicated wait-listing process.
BY CAR & DRIVER
If you're using Delhi as the starting point for a tour of India, we would recommend hiring a car with a driver as the best way to see the country. It's cheaper than hiring a self-drive car, and the drivers usually arrange their own accommodation and food. Be warned: self-driving might seem appealing, but the Indian drivers' way of overtaking each other at breakneck speed on the very narrow roads can be hair-raising, to say the least… Driving is generally slow but the distances aren't huge. Traffic drives on the left. The other main advantage of having a driver (apart from not getting lost) is that hawkers, seeing you are with a local, give you space where they might otherwise hound you.
We'd recommend contacting our Tailormade Tours Operator, who can arrange a car and driver for you. We did this when travelling around Rajasthan and it was worth every penny. Our driver was knowledgeable and unfailingly polite, and he navigated the pot-holed road with easy confidence.
Travelling by bus is a cheap way to get around, but they can be very overcrowded and uncomfortable. They link all towns and cities, and you can always pick up a rickshaw at the bus stop for short hops to your hotel. There are private and state buses, each with various categories of speed (from superfast, which is slow, to superexpress, which is quite fast) and of comfort (from semi-luxe, which is cramped and hard, to deluxe, which has 1 fewer seat per row, seat padding and air conditioning).
There are taxi-cars, with or without air conditioning, and a large number of auto-rickshaws (noisy but nippy three-wheelers) on the roads. Agree to a rate before starting your journey and make sure the driver has a clear idea of your destination. Fares are cheap with various small extras. Some drivers try to stop off at shops where they get commissions on your purchases, while others fend off all touts and take you straight to your destination.
Almost every non-Indian needs a tourist visa from their embassy or consulate. There are 3- and 6-month multiple-entry and single-entry visas (the cost is the same), and they can no longer be issued the same day - so plan ahead!
The most common health problems for visitors to India are diarrhoea and sun-related problems. It's important to drink a lot of bottled water (tap water isn't safe to drink) and protect yourself from the sun. Also be aware of what, and where, you are eating. Choose fruits that you can peel and avoid fresh salads (or wash them yourself with purified water) and ice made from tap water. Be cautious of ice cream, cold milk and undercooked fish or meat. If you experience diarrhoea it's very important to replace lost fluids and, in the case of severe diarrhoea, lost minerals and salts (it’s a good idea to go prepared with some oral rehydration salts). If you become ill your hotel should be able to recommend a good local doctor or clinic. You may want to consider carrying an emergency treatment pack including needles and syringes.
It's important to seek medical advice at least 6 weeks before departure as some vaccinations may require more than one injection. Make sure you're up to date with vaccinations for diphtheria, tetanus and polio. Vaccinations for hepatitis A, hepatitis B and typhoid are also advisable (note that the current vaccine against cholera offers very low protection and isn't usually recommended). Consider vaccinations against rabies and Japanese B encephalitis if you're planning to stay longer than a couple of weeks.
Malaria is a risk in Delhi and most other areas of India - your doctor will be able to advise you on appropriate anti-malarial medication. Insect repellent is essential; use one containing DEET.
Many staff are paid very low salaries and expect to be tipped. In hotels and restaurants, 10% is normal. In other situations, where there is no bill, a few rupees will suffice.