In scheduling a visit to any location, there are two key variables to consider: temperature and precipitation.  Ubud is no different.

There are several quite different data sets on the web for rainfall, while the temperature data look both reasonable and consistent.  The different rainfall numbers can be seen in easy to read graphic formats on: http://www.world66.com/asia/southeast... and http://www.myweather2.com/City-Town/I....  Lonely Planet tends to fall in the middle.

Temperature

The temperature in Ubud is fairly constant throughout the year

  • The average MINIMUM monthly temperatures vary from a low 19 (C)/66 (F) in July and August, to 23 (C)/73 (F) October to January. 
  • The average MAXIMUM monthly temperatures range from 31 (C)/88 (F) to 33 (C)/91 (F).
  • Conclusion:  it's always pretty warm, with cooler evenings in July and August.

Rainfall

To illustrate the data differences, myweather2 (above) reports an average 191mm (8 inches) of rain in the peak rainy month of January, while world66 reports a whopping 1065mm (about 40 inches).  Lonely Planet is in the middle at 400mm.  The U-shaped variation looks about right in all of them.  Based on 20 years experience, 40 inches sounds like too much, and 8 inches is too little.  But until the official numbers can be obtained from the Government's Meteorology Bureau, suffice it to say that there is generally wide variation in rainfall over the course of the year.

  • The heart of the rainy season occurs from January through March, when you can expect more than 15 rainy days per month (see myweather2 for the number of days with precipitation each month).  That said, the average day will have a period of sunshine (often in the mornings) in between the rains.
  • The dry season includes June through September, when Bali receives little rain each month -- just enough to keep things green -- and only 2-5 days per month with any rain at all.
  • April-May and October-November are the transitions between wet and dry, and you can expect 6-11 days with precipitaiton in each of those months.
  • Global Warming Caveat:  These trends are based on historical data, and there was nothing average about 2010.  Dry season was pretty much limited to a couple of weeks at the end of August & beginning of September.  2011 is looking much better.

What does all this mean?

Weather-wise, the best time to visit Ubud is during June-July-August-September.  The weather in July & August (peak season) is sunny and very wam during the day, and generally clear and cool in the evenings.  Ladies should consider bringing a light wrap for the evenings.

The months of July and August have great weather and coincide with summer holidays in Europe and North America, and this is when Ubud is most crowded.  Confirmed hotel bookings are a must, and reserve tables at the better restaurants in advance.  Traffic is always an issue in Ubud (there is only one narrow road through the center of the town and it's instantly jammed by just one bus), and it is worst during these two months.  The best traffic advice is to come into town early in the morning or in the late afternoon and evenings, and avoid mid-day if at all possible -- especially during July & August. 

September is really tops -- dry, cool-ish, and without the August crush.

April and May have generally nice weather, and things are less crowded.  You can often get discounts on hotel bookings.

October and November have similarly nice transition weather.  The Ubud Writers and Readers Festival is usually held towards the end of October (check their website for specific dates), and all of Ubud is typically booked solid for that week (only).

The humidity can start to increase markedly along with the rains around the end of November-first of December, and visitors during the rainy season might usefully consider scaling down their activity schedule because it's too hot & humid to be very active.  And maybe bring your travel Scrabble set for those rainy afternoons.