Goa has a typical tropical climate characterized by hot and humid summer, a short but consistent spell of rain followed by a pleasant winter. April to June is the summer season when the temperature often goes close to 35°C with high percentage of humidity. July-August is the rainy season which provides a much needed break from the soaring heat. The weather turns sober from September onwards. November to January is the winter season which is regarded as the peak tourist season in Goa. The temperature remains pleasant throughout March before the summer days make their presence felt.
The best time to visit Goa is during the winter season between November and January when the weather is cool and dry, and the sea is calm and clear. However, it is also the time when Goa sees hordes of tourists. The Goa tourism industry is in full bloom during this period. Hotel tariffs and other costs shoot up during this time, so finding a budget accommodation could become a difficult task.
For budget travellers and backpackers, the summer days are the best time to visit Goa - provided you are not afraid of venturing out under the hot sunshine. If you would like to avoid the summer days and still travel within a modest budget, then I would suggest you to plan for the trip in September-October, which is a low season. The beaches would be somewhat less crowded and the hotels/resorts will be reasonably priced.
February-March can be another good period to visit Goa. The Goa Carnival festival usually takes place by the end of February. There aren't too many tourists around after the festival gets over, so you can get some good discount on hotel deals and enjoy the lovely beaches of Goa without the mad rush of tourists.
Regards,
Deb