Visit a meteorological website for your area. Several weather forecasting websites have climate information for the recent past. If you want information from the last decade, this is one of the easiest ways to get this information.
Check a website that allows you to create a climate map, such as the Earth System Research Laboratory (esrl.noaa.gov). This website allows you to enter a range of dates to chart past climates, starting with 1895. Enter a range of dates in the appropriate box. For more specific information, enter only the years you want information for and click on the drop-down boxes to select specific months. You can also choose to chart specific variables such as precipitation. Click on the button marked "Create Plot" for a climate map. This data comes from past climate records.
Visit a website with extensive information about the climate in the past centuries. By looking at ice core samples, for instance, climate scientists can determine the climate far into the past. Websites such as the Environmental Protection Agency (epa.gov) have charts and graphs for past climate data going back over 1,000 years.
Examine the rings on a section of tree trunk. Each ring on a freshly cut section of tree trunk represents one year of growth. Counting backwards from the trunk's edge allows you to determine a specific year. Thicker rings mean ideal growing conditions for that tree species. Research that specie's ideal growing climate. Compare the width of a ring to the ideal growing conditions to roughly determine what the climate conditions were in a given year.