The Climate of Middle-Earth

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Find the sequel, which allows you to see the climate of all of Arda, HERE.

Have you ever wondered what the climate of Middle-Earth would be like? Well, I have done some research on the Internet, and it turns out that researchers at the University of Bristol were also curious. So, they loaded the world of Middle-Earth (complete with its topography and bathymetry) and let it run for the equivalent of ~70 years on the supercomputer. Here's the results they came out with:

Temperature

The average temperature of Middle-Earth in degrees Celsius.

As you can see from this temperature map, the desert of Near Harad is expected to have an average temperature of about 30 degrees centigrade, and Forodwaith is expected to be very cold (even with no influence of Melkor's magic). The Shire would have an average temperature of about 6.7 degrees Celsius, although certain areas of the Shire might be colder/warmer than others. For example the North Downs would be a lot colder than the rest of the Shire, with a yearly average of about 0-5 degrees Celsius.

Travelling west to Lindon, the average temperature remains similar, but the extremes are lower (winters are warmer, summers are cooler). In the far south-western part of Lindon, the average is 10-15 degrees Celsius. Going even farther south, to Rohan and Enedwaith, the temperature is quite warm all year round; it averages between 15 and 20 degrees, with Gondor slightly warmer.

Travelling east of the Shire, the average temperature stays relatively constant until you reach the Misty Mountains, although the area just east of Rivendell is exceptionally cold. As you go east of the Misty Mountains, you get into a much more continental climate. Summers are still pretty warm, but winters are a lot colder, this makes the average temperature of areas such as Mirkwood a lot lower than, for example, Eriador.

Precipitation

The precipitation of Middle-Earth, in millimeters per day.

Looking at this map here gives results that are very similar to what you'd expect; coastal areas and the western slopes of mountains (especially the Misty Mountains) are the wettest areas, and areas to the east of those mountains are relatively dry. Surprisingly, Gondor has high annual rainfall despite its high temperature. However, to properly understand the average temperatures and precipitation, we also need to know the prevailing wind direction:

Windspeed and direction

The prevailing winds of Middle-Earth at the surface, along with 500mbar heights.

This map gives the prevailing windspeed and direction at the surface level, along with the average heights at 500 mbar (which is at an altitude of about 5500 meters, which correlates roughly with temperature). Tolkien was absolutely correct when he said that the Elves would have been able to sail from Mithlond to the Undying Lands -- the prevailing wind direction in the Gulf of Lune would be an easterly. The same would hold true for most areas west of the Misty Mountains and north of the White Mountains (the above reason is also why Lindon would be relatively cool in winter, despite being close to the warm ocean). However, once you go down towards Gondor, the prevailing wind switches to a powerful sou'wester. The direction that the winds blow also strongly suggests that Lindon and western Eriador would be very stormy in winter, and that a powerful area of low pressure would tend to develop just west of Lindon (similar to what forms near Alaska in the winter). Conversely, a strong area of continental high pressure would form over Mirkwood. The wind direction over Minas Tirith, however, comes from the south and west, therefore Sauron could not have sent dark clouds from Mordor in that direction unless a low-pressure system happened to stall out just to the south of Mordor (think Hurricane Dorian's stall over the Bahamas in 2019).

There would be some large, fairly permanent weather systems in Middle-Earth. They would include the:

• Lindon Low, off the coast of Lindon. A strong low-pressure system that would bring frequent powerful storms (think nor'easters) to the western shore of Middle-Earth in winter. Most likely strongest during winter, and relatively weak during summer.
• Rhun High, over Western Rhun. Keeps things relatively warm in the summer, but is likely to become fairly weak in the winter, resulting in colder winters.
• Bay of Belfalas Low. Brings relatively frequent rain and cloud cover to the coast of Gondor, especially in winter. Similar to the Lindon Low, although not as strong.

Vegetation

The predicted vegetation of Middle-Earth.

Here's where the weather science really becomes interesting, as this map describes what kind of vegetation one would expect to find in Middle-Earth. Most of the trees would be broadleaf trees, however, large areas of Enedwaith and Minhiriath would have mostly conifers. Mordor would be mostly shrubland, even with no dark clouds from Mount Doom.

How could this be useful?

Maybe, this climatological and biological data could be useful to make the world of Middle-Earth more authentic, provided, of course, that it doesn't interfere with the lore of the books.

These models do not take magic and great evil powers into consideration, so they may not be 100% accurate, but they should be interesting and give you an idea about how the world of Middle-Earth might have looked.

For comparison, here's Karen Wynn Forstad's map of the climatological zones of Middle-Earth from her atlas:

Middle-Earth's climate regions, according to Karen Wynn Forstad's atlas.

On the whole, Karen's and Tolkien's climate descriptions closely match what the computer models would predict.

Glflegolas, M.Sc. (admin) ^{Send a Messenger}

15:52, February 5, 2015 (UTC)