When To Go
The decision of when to travel involves a multitude of factors. If you have a limited window of time in which to travel, then focusing on where you want to travel becomes a more important question. If your itinerary is more flexible, then it’s possible to take other issues into consideration.
Whether it's the high, low, or "shoulder" season in a particular destination can greatly affect the cost and the quality of your trip. If you plan to visit a popular destination during the high season, it goes without saying that you will pay more for airfare and accommodations than you would in other parts of the year. You also might be forced to endure long lines in various points of interest. If you wish to participate in many outdoor activities then the high season may be your safest choice.
The shoulder season is the couple of months on either side of the high season and can be an excellent time to find decent prices on lodging and airfare. Although usually not considered an ideal time, the low season can actually be a good time to visit a place—particularly an expensive one with lots of indoor activities like museums. However, it’s important to keep in mind that in some parts of the world the low season can mean scorching hot temperatures, monsoon floods, or bitter cold.
Online Resources For When To Go
Weather.com Global Destination Weather
This site offers a search interface that allows you a multitude of searching options for travel. Using the destination finder, you can search a particular temperature range during a certain month of the year any place in the world. You can also search by a specific destination or by a set of available themes such as "Exotic Asia" or "Beach Bum". Very useful!
This site gives you statistics like average temperature and precipitation for certain times of the year. Keep in mind that "average" temperature can be misleading as the days can be very hot and the nights very cold in certain places. This site should only be used as a general guideline. It is best to check current weather.
A place to find the time anywhere in the world. Also has a link to weather all over the world.