Warm Weather Appears to Restrict Coronavirus Infections In a Major Way

As we enter the month of May we now have two solid months worth of data on the coronavirus in the United States and we're starting to learn some things about the virus based on that data.

For instance we now know the coronavirus is far more common and far less deadly than the experts initially believed -- as I wrote about earlier this week -- and we also are learning that the outbreak in New York City is without parallel in terms of severity with any other major city in the world. We also now know the outbreak in New York City is certainly without parallel anywhere else in the United States. (Heck, it it doesn't even have a parallel in upstate New York, where infection rates have been minimal.)

Of course this data also leaves us with as many questions as it does answers. While we know the outbreak in New York City is the largest in the world, we can't say for certain what it is about New York City that made it such an outlier in the world and this country.

New York is certainly the most dense city in the United States and density appears to certainly aid in viral transmission, but San Francisco is the second most dense city in the country and has seen almost no deaths at all. (Yes, San Francisco shut down a few days earlier than New York, but are those few days really the sole difference between tens of thousands of deaths in New York and a handful in San Francisco?) Yes, New York also relies on public transportation more than most cities, but London and Tokyo and many other large cities that are equally as dense and had their first infections around the same time also rely on public transportation to a substantial degree. And neither London nor Tokyo has seen a viral outbreak anywhere close to New York's.

Furthermore, it's certainly not the fact that the virus began in New York first. We know the virus was on the west coast long before it was on the east coast and none of the places on the west coast have had an outbreak anywhere close to New York's either.

So maybe it's a combination of the the density and the public transportation, but it also seems like another major factor is at play here when you consider the United States outbreak rates -- the weather.

New York appears to lie in a fertile temperature range that aids in the transmission of the virus.

According to Yahoo News a government test of the virus in a variety of weather conditions found: "the risk of “transmission from surfaces outdoors is lower during daylight” and under higher temperature and humidity conditions. “Sunlight destroys the virus quickly,” reads the government briefing, which was published by Yahoo in mid-April, but didn't receive very much media attention.

So has this government test been reflected in United States data?

Well, let's look at the numbers in the South and the West, where it is, on average, warmer and there is more sunlight, compared to the Northeast and the Midwest, where it is colder and there is less sunlight.

Here are the deaths per million for the individual states which allows us to adjust for population and compare everyone across the country evenly. (There is certainly an argument that some states are reporting coronavirus deaths more aggressively than others, but the adjusted population numbers make that less significant, especially when you see how much more New York City and the surrounding regions were impacted by the coronavirus than other parts of the country. This also eliminates the necessity of considering total cases, since cases are in many ways a reflection of the number of tests that have been given.)

Here are the deaths per million through May 1st as reflected in the worldometer website calculations for the 13 states in the country with the highest rates of death.

1. New York state -- almost all of which is New York City -- 1,242 deaths per million

2. New Jersey -- almost all of which is connected to New York City -- 872

3. Connecticut -- New York City again -- 653

4. Massachusetts -- 583

5. Louisiana -- 427

6. Michigan -- 404

7. Washington, DC -- 351

8. Rhode Island -- 280

9. Pennsylvania -- 217

10. Maryland -- 208

11. Illinois -- 200

12. Indiana -- 185

13. Delaware -- 177

You'll note that only Louisiana, whose outbreak appeared to be connected to Mardi Gras back in February when it wasn't very warm in the South yet, is on this list from the South or West and that the rest of the states with the highest death rates are in cold weather climates. You'll also see that New York City and its bedroom communities are off the charts compared to everywhere else. (In fact, New York City is off the charts compared to every major city in the world. If you take away the outbreak in New York City, the United States would be better off than just about every country in Europe. Even with New York City included the United States has still been far better than Italy, England, Spain and France when it comes to the coronavirus death rates per capita).

Well, how about the death rates per a million people in the South and the Southwest, where the weather is warmer?

Georgia is at 114deaths per million, which is a fraction of most of the states listed above, but is the highest in the South outside Louisiana.

Mississippi -- 97

Nevada -- 87

Virginia -- 73

Florida -- 66

Missouri -- 59

Alabama -- 59

Kentucky -- 56

California -- 55

South Carolina -- 54

Arizona -- 50

North Carolina -- 42

Tennessee -- 31

Texas -- 30

Arkansas -- 24

Hawaii -- 11

(The western states of Wyoming, Montana and Utah have the lowest rates of death in the continental United States, but that is likely to be a function of their rural nature as opposed to their weather.)

Now you can certainly argue that the states in the South and West are still destined for major outbreaks, but this is the same argument that has been made for months. And it really doesn't make sense that an outbreak would suddenly occur as we move closer to summer and the weather gets even warmer after these states have had the virus for multiple months without an outbreak.

You'll recall that Florida, in particular, was supposed to be ground zero for the next major coronavirus outbreak in the United States -- Italy on steroids, as many called it -- yet no major outbreak has ever happened. Indeed, the death rate for Florida is very similar to another large state whose governor has received massive praise for his coronavirus response -- California.

Tomorrow Florida restaurant and retail stores open back up in much of the state and the beaches are already open as well. In his announcement opening back up the state Florida governor Ron DeSantis shared all the data which shows how much better Florida has weathered the coronavirus outbreak than states in the northeast:

While DeSantis certainly didn't end up deserving any of the media condemnation that rained down upon him and likely has made good decisions based on the data he saw in his state, what can explain why Florida, which was slow to close down and quick to reopen, and many other Southern and Western states, have seen limited outbreaks compared to the states in the Northeast and Midwest?

I think the most likely factor is the weather.

The potential impact of weather has been discussed surrounding the coronavirus since Donald Trump theorized warm weather was likely to diminish the viral spread months ago, but it hasn't been discussed as much as it should have been -- perhaps because it's been considered a political argument ever since. Indeed, many in the media may have been less likely to discuss this data precisely because they are loath to acknowledge that Trump has been correct about anything surrounding this virus at all.

This is a shame because the data pretty strongly suggests that Trump was right about this, the data is showing us that the virus does appear to spread much less significantly in warm weather than it does in cold weather.

What's more, this shouldn't be a huge surprise since most coronaviruses -- and viruses in general -- spread much less significantly in warm weather than they do in cold weather. So far from being an outlier, this is what we would expect to be the case with this virus.

It's possible government officials haven't wanted to discuss this data because they feared it would discourage states with warmer weather from social distancing and staying at home, but we're not just seeing this data in the United States, we're seeing it around the world as well.

Look at the viruses rate of death in tropical or warm weather countries with large populations and dense cities:

Brazil -- 30

Mexico -- 15

Nigeria -- 11

Saudi Arabia -- 5

Australia -- 4

Indonesia -- 3

South Africa -- 2

India -- .9

Kenya -- .4

Venezuela -- .4

Putting these Brazil and Mexico death rates in total numbers, Brazil has had 6,434 deaths, Mexico 1,972 deaths. (I'm not saying these warm weather countries can't get worse in the months ahead, but I am saying that so far they haven't and the longer they go without major outbreaks, the less likely it would appear to occur as summer arrives across much of the world. The only country in Latin America that has had a remote issue at all is Ecuador, and even Ecuador is a pinprick of what we've seen in the United States, notching a death rate similar to Virginia).

Even if you presume these countries above may be undercounting their deaths and rates of infection, it's still fair to say that none of these warm weather countries has had any substantial issue with hospital overcrowding or massive social unrest as a result of the virus. Furthermore, these aren't just outlier countries, this is true of the smaller tropical countries as well. All of them are a pinprick of the outbreak that we've seen in much of the northeastern United States. You can check the data for yourself here.

So if the weather is truly important when it comes to the viruses spread, as the data clearly seems to suggest it is, why isn't this being talked about more in the media? Especially as it pertains to the return of college students to campus and athletics, which are seeking ways to restart their seasons or thinking about what the virus impact might be on football in the fall. Rather than, for instance, talking about starting the football season later in the fall or winter when cold weather would aid the viruses spread colleges, as well as the NFL, should be talking about starting the football season earlier.

We also need to consider that the coronavirus impact is likely to be more significant if it returns in the fall in the Northeast and Midwest, which have much colder falls and winters than the South and the Southwest. More significant precautions may need to be undertaken there than elsewhere.

Heck, instead of talking about pushing back the return of students to campus later in the fall, colleges and universities should be talking about getting their students back on campus as early as they can so they could finish the fall semester before it gets very cold and maybe even start the spring semester later than normal so that it runs into more warm weather.

These are smart debates we should be having right now based on all the data we are seeing in our country and around the world.

This could also impact the debate in states like California, which are severely restricting their citizens from going to the beach and walking in state parks. With warm weather and sunlight pouring down all over California right now, the risk of outdoor infection at beaches and public parks would be incredibly small. Especially compared to the health benefits of being active outside as opposed to cooped up indoors. In fact, the data might well reflect that instead of staying indoors in cool environments where the virus may spread easier among those in close contact, it might well be that governors should be encouraging their citizens to get outside and circulate.

Should retail stores pull their offerings out on the sidewalk, open the doors, and encourage shopping there rather than inside a closed and cool environment? Should restaurants encourage patrons to eat outside on their patios as opposed to indoors? These are smart conversations we should be having based on the data, but right now we aren't having those conversations.

Because right now the data is pretty clearly showing us that the coronavirus is likely to be far less contagious in July and August than it is in, let's say, December or January. Which is why far from pushing a fall football season back, colleges and the NFL should be considering starting the season earlier and finishing it earlier as well.

We should also want college kids on campus as early as possible, as close to summer's peak as possible.

And in a larger context the governors of our states should be trying to get their citizens back to work now so we can get the economy rolling in the summer, when the rate of viral infection is likely to be much lower than it is in the late fall and winter.

We have to let the facts lead our conversations about the coronavirus, not our fears.

And right now the facts are telling us that the viruses impact is not going to be as severe among the young and healthy or among those of us who live in warmer climates.

We need to adjust our policies accordingly.