It might sound like just tourist board PR, but it's true: any time of year is good for visiting Amsterdam. However, there are clear pros and cons of coming in the different seasons, and specific events you might want to bear in mind when planning. For a detailed calendar of events see www.iamsterdam.nl.
Blooming in spring
Come March, things usually start to warm up a bit after winter, and cafés and bars start putting their tables and chairs out on their canal-side terraces. Mid-March through to May is also the time of year to gawp at the blocks of intense colour to be seen in the bulb fields a short drive south-west of Amsterdam, and the famous Keukenhof gardens (www.keukenhof.com) - best time to visit for tulips is normally mid-April.
Festive in summer
Amsterdammers really make the most of warmer weather. On fine weekends and evenings in summer, they can be seen chugging round the Grachtengordel (the Canal Ring) in their battered old boats with beer in one hand, tiller in the other, and socialising out on the decks of their houseboats and on the steps of their gabled homes. They also head out to nearby beaches - Bliburg (www.blijburg.nl) is just 15 minutes by tram from Centraal Station, the resort of Zandvoort half an hour. And they hang out in Amsterdam's main green space, the Vondelpark, whose summer attractions include free music and dance and performances for children in an open-air theatre (www.openluchttheater.nl), and outdoor movie screenings courtesy of the EYE Film Instituut Nederlands - see more on my Amsterdam nightlife page.
Thinning crowds and cultural nights in autumn
September is a good month to visit Amsterdam. If you're lucky, it will still be nice and warm, and at the same time you're likely to have a bit more elbow room in top attractions such as the Van Gogh Museum than in the peak summer months. Go the third weekend in September (16-18), and you'll be around for the Jordaan Festival (www.jordaanfestival.nl), a jolly street festival in arguably the city's most enticing neighbourhood.
Affordable and snug in winter
November to March are low season months in Amsterdam. That means hotel rates - and airfares - are at their cheapest (particularly on weekdays), it's easier to bag a room in the city's most desirable canal house hotels, and the queues to enter top attractions are at their shortest. (Though even in the depths of February, at weekends still expect a wait to get in to the most popular places such as the Anne Frank Huis and Rijksmuseum).
The downside of visiting in winter is that it can be very cold, and with much of the city below sea level, that can often mean a bone-chilling, misty dampness. Yet on the plus side, every so often the canals freeze over to a thickness that allows you to skate along them - it happened in January 2010 for the first time in a decade - and those icy blasts off the North Sea are the perfect excuse for holing up in one of the city's many unimprovably snug bars.