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Historical Worldwide Climate and Weather

Long-Term Climate Map

Click on above map to see long-term temperature cycles dating back to 2500 B.C.

  Select Date Range (600 B.C. to 2000 A.D. available - more historical updates soon)

The information on this website shows weather and historical trends from approximately 600 B.C. to the present day. Much of this data was put together by the Weather Science Foundation in Illinois back in the early to mid 1970s. At one time, over 60 people were employed to gather worldwide data.

Unfortunately, funding for this project evaporated and the Weather Science Foundation shut down its operation. However, some of this unique information was given to Climatologist Cliff Harris. By an agreement, Cliff did not use or publish any of this information for 30 years.

The Weather Science Foundation worked with the climatology of the Earth. The science of climatology deals with the ‘statistical’ side of the weather. It involved the long-term research of a particular region’s or Earth’s climate. Many factors were studied to arrive at their conclusions, such as sea-surface temperatures in the oceans, particularly in the Pacific (El Nino and La Nina), dendrochronology (tree rings), volcanic cycles, tidal cycles, solar ‘sunspot’ cycles, lake bed data, core samples, human migrations, ancient writings and so forth.

The study determined, according to the Weather Science Foundation, that our planet goes through long and short term weather cycles that ultimately affect human behavior, migrations and widely-fluctuating economic patterns like we’ve seen recently. See chart.

There were four distinct type of patterns that were noted since 600 B.C., ‘warm-wet’, ‘warm-dry’, ‘cold-wet’ and ‘cold-dry’ cycles. Also, about every 500 years, our planet also goes through a cycle of Wide Weather ‘Extremes’. Our current cycle of extremes is been the worst in 1,000 years, since the days of Leif Ericcson, the mighty Viking explorer.

A ‘Warm-Wet’ cycle is the best cycle for global prosperity and strong leadership. During this period, global temperatures are warmer and global precipitation will be a little higher than normal. Since the 1980's, global temperatures are over a degree warmer, which has fueled the debate over ‘global warming’. However, people’s moods are usually better in warmer and wetter times which tends to ‘bullishly’ affect the stock and commodity markets. During the 1990s and early 2000s, there was tremendous economic growth across the world. With the exception of the Iraq war, much of the planet enjoyed relatively peaceful times.

A ‘Cold-Wet’ cycle does have some growth, but migrations do increase as temperatures are generally cooler than normal. However, with more moisture, many counties still thrive, but again, the ‘warm-wet’ cycle is the best one for growth and prosperity.

However, as the saying goes, "sooner or later, all good things must come to an end." Well, the bad news is that we’re looking for the worst climatological cycle, or a ‘Warm-Dry’ phase to occur. And, as we transition from the ‘Warm-Wet’ phase towards the ‘Warm-Dry’ one, we may see ‘extremes’ that will make this current cycle of ‘extremes’ look like a walk in the park.

A ‘Warm-Dry’ cycle typically means that temperatures on a global level are a little warmer, but precipitation is noticeably less than average. During this time, there are massive worldwide droughts and crops are severely strained. Studies have indicated that when we have experienced warmer and drier conditions, you often see a period of ‘bad times.’ As a result, there are usually ‘bad’ leaders, as was the case in World War II when Hitler and Mussolini dominated the European continent.

Our last major ‘Warm-Dry’ phase occurred during the 1930's. Of course, many do remember the infamous ‘Dust Bowl’ and worldwide drought and depression. This pattern completes a 102-year cycle which dates from 1936. And, if history is any indication of what’s to come, our chart says that we could see a huge stock market crash, global depression, new outbreaks of unknown disease, and perhaps, a third World War if we stay warm and precipitation levels fall on a global scale sometime between 2020 to 2038.

‘Cool-Dry’ phases are also bad, not as severe as the ‘Warm-Dry’. Precipitation is still below average during this cycle, but temperatures are cooler than normal. During the 1980's, we went through a period of cooler and drier than normal weather. During that time, the stock market hit its lowest level since the Crash of 1929. There was three severe droughts in the Corn Belt during the 1980s, 1980, 1983 and 1988. Plus, we had volcanic eruptions that particular decade and widespread political unrest. Many people that we’ve talked to have said that they would like to "forget the 1980's weatherwise and otherwise."

 For more information, please email us at if you have any questions about the services available from Harris-Mann Climatology.