A good approach to determine what type of weather to expect on your trip to Alaska is to look at the climatology of the location(s) you expect to visit. Climatology does not attempt to predict the weather for your trip, rather show you what the historical averages are. If you are a new visitor to Alaska, then a good place to start is here, and this will give you a good idea of the general weather conditions for the location(s) and time of your visit. Climatology data should also be considered with a critical eye and all weather elements available should be taken into account. For example, let's say you are going to visit Juneau and Fairbanks in July. You will find that on average Juneau has 17 days with precipitation while Fairbanks has 12. You may then think that Juneau is only a little wetter then Fairbanks for this period. However, if you also consider the average precipitation in July you will see that Juneau has 4.16 inches of rain, and Fairbanks only 1.87 inches. Hence Juneau receives more than twice the rainfall in an average July than Fairbanks. The point of this is not to belittle Juneau`s weather, rather to make the lay person conscious of the problems interpreting the climatology data. Many people will find it useful to compare the climatology data of their destination(s) with the data for, or near, their home town. This provides a basis of reference. For instance, you may find that summer in Fairbanks is like spring at your home, then you would bring clothes you find comfortable for this type of weather.