My favorite almanacs are easy to use and contain thousands of city listings. The best site I've found that displays raw data of previous years is maintained by the United States government at the National Climactic Data Center . The main parameters include temperature, precipitation, pressure, visibility, and wind information. At both sites you will need to accept the terms and conditions of use before proceeding. At the very least, it will tell you the maximum and minimum temperatures so you can dress appropriately, and the precipitation amount so you know whether to bring an umbrella or snow snoes.
Many companies now provide customized long range forecasts and research.
In this case, you can actually get a decent amount of information with just a few clicks. From 6-10 day forecasts up to a year in advance, check out these links in the Extended Forecasts area. Limitations Using the resources listed above may not help you determine if it will sprinkle or shower during your trip or forecast date, but it will provide the major planning points such as maximum and minimum temperatures, precipitation totals, wind speed, etc. As you get closer to your trip or forecast date, be sure to fine tune your long range forecast with the recommended short range forecast sites specializing in United States or International territories. Real feedback wanted about your Allergy experiences.