World Climate Guide

This guide is about the world's climate and how it can impact upon your plans. Frankly, it will tell you little more than you could have found out yourself by spending a day on the internet, but it could save you a lot of time.

The climate is important to many people operating internationally. If you are planning to retire to a foreign country, is it agreeable? Is it agreeable all year round? If you are investing in holiday accommodation, is the season long enough to warrant your investment? If you are selling rainwear, will there be a market?

To make matters more complicated, everybody has a different view of what is a “good” climate.

Fortunately, the internet is full of good sources of information about climate. In addition, there is lots of climate information in our country-specific climate guides.

In this guide we are looking at some of the broad trends that might affect you.

Worldwide Data

We refer you to the excellent World Weather Information Service, which displays climate details for most of the world in a consistent format. It has information about over 5,000 towns and cities.

A good alternative – more easily customised to see temperatures month by month but covering fewer places – are www.holidayweather.com’s averages tools.

Probably a better alternative – because it records hours of sunshine as well as humidity and temperature – is www.weather-and-climate.com.

General Considerations

By and large, people are looking at seven factors when thinking about whether a particular climate will suit their needs:

  1. Maximum Summer Temperature
  2. Average Daytime Summer Temperature
  3. Summer Humidity
  4. Minimum Winter Temperature
  5. Average Daytime Winter Temperature
  6. Rainfall: month by month
  7. Sunshine: month by month

I will look at each in turn.

Maximum Summer Temperature

Most people will probably accept the odd exceptionally hot day. However, it is probably worth checking out the record temperatures in the places of interest to you. Some are frightening! I have been in Dubai when locals claimed it was the hottest day ever and 57°C. It was appalling. It was also, in truth, probably only 50-52°C. People get very macho about these things! God knows what a genuine 57°C would be like.

Incidentally, if you’re from a place that is confused by all this °C stuff, it’s handy to keep RapidTables or similar open in another tab.

Average Daytime Summer Temperature

This is, perhaps, the most important factor for most people.

Each of us has his or her comfort zone. For me, 25°C is enough but my next door neighbour looks for holidays where the temperature is 40°C or higher. However, there are some general statistics that might be important to you if you are thinking of running a tourism related business or investing in property for vacation use.

Some academic research has been carried out. An interesting – and short – piece is by Susanne Becken: The Importance of Climate & Weather for Tourism.

Z. Mieczkowski, from the University of Manitoba, has produced “The Tourism Climatic Index” by aggregating a series of other indicators to give an overall measure of the suitability of a particular place for tourism. In this index, monthly averages of seven climate variables relevant for tourism are integrated into five sub-indices: daytime comfort index, daily comfort index, precipitation, sunshine, and wind. All of them are rated on different scales and then combining. $6 well spent if you are seriously interested in this topic! It has since been adapted to be more relevant to particular countries.

Later work identified the Physiologically Equivalent Temperature (PET) index, which was developed for outdoor applications and after testing lots of people to see at which point people felt uncomfortable.

A graph showing PET values

Categories of the PET values (°C) for different grades of thermal sensation and
physiological stress level of Western and Central European people (based on Matzarakis
and Mayer, 1996). Taken from Quarterly Journal of the Hungarian Meteorological Service (PDF)

So I am normal after all!

Summer Humidity

As relative humidity (“RH”) approaches 100% the air is fully saturated with water vapour and can take no more. So you can’t sweat and, of course, sweating is one of our human mechanisms for keeping cool. Humans like an RH of about 45%.

There are lots of online souces for the present RH readings for particular places or for historic local RH readings but, to give a general picture:

“It doesn’t take that many degrees of global warming to permit peak heat to (occasionally) become unsurvivable in many parts of the world that are currently highly populated”. So says the University of New South Wales. See their paper here.

A short quote from it:

“We came to this conclusion by considering a meteorological quantity called the wet-bulb temperature. You measure this quantity with a normal thermometer that has a damp cloth covering the bulb. It is always lower than the usual or “dry-bulb” temperature; how much lower depends on the humidity. At 100% humidity (in a cloud or fog) they match. In Sydney and Melbourne, even during the hottest weather, the wet-bulb usually peaks in the low 20’s C. The highest values in the world are about 30-31C, during the worst heat/humidity events in India, the Amazon, and a few other very humid places.”

This image shows their findings of current peak “wet bulb” temperatures:

A world map chart highlighting areas of high heat and humidity - the worst bits are mainly in South America, Africa, and South Asia

Red can feel very hot and humid.

Minimum Winter Temperature

As with summer temperatures, record low winter temperatures can surprise.

Average Daytime Winter Temperature

This may be of little concern if you are running a ski resort – though even there “too cold” can be a put off. However, it is a key factor for the huge “over-wintering” and winter tourism markets.

See www.holidayweather.com. Remember that, in the southern hemisphere, January is summer. I don’t mean to treat you as stupid – when I was the editor of the leading industry magazine we ran an article with the wrong data. Embarrassing.

Rainfall: month by month

See the World Weather Information Service guides.

Sunshine: month by month

The number of hours of sunshine, especially during the winter months. is as important as the temperature when people assess the desirability of a destination.

See www.weather-and-climate.com for details of the sunshine (and humidity and temperatures) in hundreds of places round the world.

Conclusion

The climate is important for many people. I remember taking my wife to Greece in the winter. She packed a bikini. She would have been better off with snow shoes. It wasn’t just the weather that was frosty!

If you are moving abroad to start a business the weather can be critically important. At least you now have the facts.

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A lightning storm over a beach and distant city. The sky is purple and orange.