COVID-19 may not stop in Summer

One factor I have been watching closely is the spread of the coronavirus through summer or tropical countries. For most of February, it appeared travellers brought COVID-19 to summer or tropical countries, but the spread within those countries was limited. That looks to be changing.

The raw chart comparing the two still suggests a stark difference:

Summer Winter COVID-19 coronavirus statistics

But other charts are showing early negative signs:

Summer Winter COVID-19 coronavirus statistics
Summer Winter COVID-19 coronavirus statistics

Quick Data background

We split cases into: 

  • Winter countries: Northern Hemisphere Countries currently in winter 
  • Summer/Equatorial countries: Southern Hemisphere countries now in summer or Countries near the equator where temperatures are relatively high all year

The data in these charts are based on where the case was caught rather than diagnosed. For example, a case caught in Iran but diagnosed in Thailand would be assigned to winter.

All of these charts are available (updated daily) for all countries here

Taking a turn for the worse

Signs are growing that tropical/summer countries are falling to the virus.

While the numbers are still low, they are snowballing.

And when you look through the countries, lots are showing the typical progression before cases really take off:

Coronavirus cases Malaysia

Coronavirus cases Australia

Coronavirus cases Phillippines

Coronavirus cases Singapore
Coronavirus cases India
Coronavirus cases Indonesia     


Scientific Background

There are suggestions that UV-B radiation and vitamin D played a role in reducing deaths in the Spanish Flu pandemic. Other studies suggest humidity greatly reduces the aerosol transmission of viruses, but some suggest humidity increases surface transmission. It is unknown how these affect COVID-19 – many experts warn against being too optimistic.

Economic Impact

There are two elements to the coronavirus:

  1. Humanitarian. The bigger the shutdowns, the greater the preventative measures, the fewer people will die. 
  2. Economic. The bigger the shutdowns, the greater the preventative measures, the more significant the economic impact will be.

In the early stages, for many countries, the focus was mistakenly on minimising the economic impact. That is no longer the case. It is about preventing the spread of the disease. Or, for politicians, at least been seen to be trying. The economy is no longer the issue.

At the moment our base case is coronavirus outbreaks will be worse in colder countries. Last month, we were hoping tropical or summer countries would mostly avoid the virus, but that assumption is looking increasingly shaky. 

I’m still assuming summer/tropical countries will be less affected medically. However, it is looking increasingly likely that those countries will need to enforce strict quarantines anyway. And so the economic impact may not be much better than winter countries. 

Investment Outlook

The economic impact may even be worse on Southern Hemisphere countries. The natural progression of the virus combined with summer may mean the threat eases in the Northern Hemisphere over the next 2-3 months. Potentially just as the virus is receding in the Northern Hemisphere the Southern Hemisphere may get an intensification with winter that requires extended quarantines.  

South-East Asia typically has increased influenza from August, so it may see the same effect.

So, caution is still the by-word.

Our impression is countries affected by SARS are dealing with COVID-19 better than those that weren’t. We expect these countries will recover more quickly. 

Damien Klassen is Head of Investments at the Macrobusiness Fund, which is powered by Nucleus Wealth.

The information on this blog contains general information and does not take into account your personal objectives, financial situation or needs. Past performance is not an indication of future performance. Damien Klassen is an authorised representative of Nucleus Wealth Management, a Corporate Authorised Representative of Nucleus Advice Pty Ltd – AFSL 515796.

Follow me
Latest posts by Damien Klassen (see all)


  1. I think because it kicked off in the northern hemisphere while it was at the tail end of their winter so its been hard to say if it would be seasonal. But you can see it is growing in Malaysia and other tropical/sub tropical countries. Also still speading rapidly in europe and middle east with warmer weather

    • The Malaysian outbreak has most of it’s cases coming from one large religious gathering. They are reacting pretty strongly to this, we’ll see how it goes with containment. Am in the country now and from tomorrow everything will be locked down, no travellers allowed in, locals can’t travel abroad, virtually all govt dept’s shutdown, schools/unis shut. No religious, sports, event gatherings allowed, domestic travel restricted and shops apart from supermarkets are being asked to close. Will be an interesting few weeks.

      As for Singapore, it’s in a tough spot due to how virtually everyone has to use packed public transport to do virtually anything. It’s hard to practice social distancing in those circumstances. They seem to have a handle on it though.

      • I do hope someone went to the Hillsong bash with a raging fever.
        Afterall….. god will sort them out in the end

  2. Jebus, we’re going full doom this morning! But excellent analysis as always – hopefully the MSM will have you on more often although I won’t hold my breath.

    As an aside: Alan Jones had a guest on this morning saying that coronavirus is a mental illness i.e. implying severe overreaction.

    (Don’t shoot the messenger – I normally permit myself a dose of 5 mins each of 2GB and ABC when I go and get my coffee in the a.m. Just to take the temperature of the world. )

    • Damien KlassenMEMBER

      The best thing about the Coronovirus “truthers” vs the Climate Change “truthers” is that natural selection will work far more quickly on the former.

      • Do you remember the days of “It only attacks Asians?”

        This has been a hell of a ride watching every single possible “we’re special” excuse from racial supremacy to “we’re first world” get utterly destroyed by the cold hard reality that people are people, and systems are systems. Both act the same way under the same circumstances.

        That’s always been my position. I firmly believed there was no difference whatsoever between the CCP and the freest democracy when push came to shove. Ignore, pretend she’ll be right, delay to past the last minute, act. South Korea may be slightly softer in their approach, but they essentially responded the same. As have the others. People are people.

        As for systems, while our systems are more robust than the third world, excluding antivirals, the treatment remains fairly primitive for the most part. Oxygen support for the not critical, and ICU for the critical. There’s nowhere on earth with enough ICUs for a full scale spread. So the ultimate difference is likely ultimately to be in the decimal point. It’s actually reasonably likely the 3rd world does better overall because their population pyramids skew young. Systems are systems. They have breaking points.

        I’m not trying to gloat, but it has been a pretty wild ride of watching with grim horror everything I expected slowly unfold. (Honestly, it’s usually best to expect people to do the dumbest things you can imagine and work within that range. I joked elsewhere about people setting up kissing booths for covid research. Scummo came pretty close with his church stupidity.)

        My partner went over a month ago from “It’s no big deal and you’re over reacting” to “thank you for telling me to get my parents overseas to stock up on food.” and cancelling out trip overseas.
        My family went from “Yeah, we should probably do something” to “Oh crap, we didn’t and now there’s no TP.”

        My only regret is trying to trade it instead of simply holding my sizable short position.

        • Regarding your point about CCP vs democracies – I think you’re right, to a point.

          I may have missed it (I’m keen to be corrected, if that’s the case), but I’m yet to see/hear the following from Italy:
          – people dragged off against their will because they have a temperature
          – residents of apartment buildings having their doors welded shut

          • Italy is charging people with attempted murder for leaving their apartments when under quanratine, Australia has implemented mandatory laws of detention and quarantine – South Australia has the right to simply throw anyone in jail to meet the states needs.

            Suggest you do some research rather than just relying on your underlying bigotry.

          • Fair point @myne, it is early days for the democratic world.

            @Itch Balm, obviously I didn’t sufficiently couch my comment in uncertainty and openness to being challenged for your sensibilities. In any case, I think that’s a false equivalence. There’s a stark difference between enforcing your quarantine (I might add that the Italian attempted murder example extends only to symptomatic persons who break their quarantine) and forcibly removing people from their homes.

          • As of last weekend and the macrovoices podcast interview with someone on the ground in northern italy, they are issuing fines and were considering short term imprisonment but that just guarantees that the virus will explode in prison populations

          • It sounds like having systems in place post-SARS is a more important factor than having a brutal dictatorship and/or compliant population.

            Anyway we’ll see.

      • bolstroodMEMBER

        CC may catch up.
        When the petro chemical pollution in the upper atmosphere clears due to lack of economci activity caused by the V, the planet will get a 0.5 degree C temp increase immediatly. The pollution has been acting as a eat shield.

    • Well you’ve outed yourself now. Buying coffee amongst all this – 1%er!

      Thanks for taking one for the team btw. I would literally rather put roofing screws in my ears than listen to Parrot Pontification.

      • I said to my other half that I was considering stopping the barista-made coffee. Then I thought that if half the people did the same, my local would fall on hard times, jobs would be at risk etc. And I’ve been going there for years.

        This one, seemingly inconsequential, example demonstrates how tough things are going to be for small businesses. If landlords hadn’t got the message before they sure as hell will be getting it in the coming months.

    • Alan Jones: Australia only contributes to 1.5% of global cases of nCoV so we shouldn’t do anything about it.
      In other news: 3% of scientists say nCoV is not real

  3. Ronin8317MEMBER

    March is already Autumn, last weekend it was 12 degrees in Sydney. Even if the theory about Summer infection is correct, it is academic now. Look at the number in Malaysia and the consequent rise in number of infected in Singapore : Malaysia is toasted.

  4. I took my car to the mechanic yesterday and they pilfered an obvious third of a bottle of hand sanitizer which was on top of the sun visor.

    People are fvcked.

  5. Bulk of the new Covid cases in Malaysia linked to a mass religious gathering attended by ~16000. All mosques & suraus to close. Better late than never.

      • bolstroodMEMBER

        Apparently a few of the passengers on Dutton’s flight back from the USA have caught the V
        And Dutton attended the Cabinet meeting 2 days after he returned.
        And then the Scrotovirus didn’t go to te footy, he went to Hillsong.
        Oh happy days ! Oh happy days !

    • codeazureMEMBER

      Exactly. At least 1500 of those were from overseas, some of which presumably could be from cold countries. So perhaps that was the seed. It was their version of running Mardi Gras & Hillsong in Sydney, crazy stuff.

      Seems like around the world religious venues are especially effective at spreading the virus. Apparently God isn’t on their side after all 😉

      • Mining BoganMEMBER

        He never was. They’re just the freaky ants he likes to burn with a magnifying glass.

    • ErmingtonPlumbingMEMBER

      Just Finnished jet blasting my first sewer choke in a about week.
      Fking new ski goggles style eye protection kept fogging up and I found wearing a respirator even more of a pain in the ar$e!
      Sprayed quarter of. Can of Glen 20 all over myself, steering wheel and gear stick afterwards.
      Can’t helping thinking my infection is inevitable if I keep working.
      Might have to double my price on Jetting jobs to keep me motivated to turn up.

  6. Regarding summer/tropical locations – it may differ between areas or cities where people spend more time indoors with aircon vs outdoors?

  7. Summer was never going to change. SImply, if like any other corona virus it would need temps in excess of 56 deg C. …. it has always always been hopeful. IMHO it does not necessarily work in reverse and cold winter temps may exacerbate in Aus