Climate and Unsheltered Homeless in the Continental United States

I got news for all the chronically housed people in the US, who have apparently never even gone camping, yet are making policy and trying to understand factors that influence where you find unsheltered homeless people: Daytime January Temperature isn't remotely synonymous with Climate.

There are many other factors involved in actual weather, not just daytime temps (much less daytime January temps). When you spend most of your time outside -- instead of just visiting it for five minutes on your way to your car -- these other factors are huge issues in terms of tolerableness of the climate.

I am in the process of reading The State of Homelessness in America (PDF). This is a report from The Council of Economic Advisers dated September 2019.

From page 17:

...rates of unsheltered homelessness are uniformly low in cold places. In other words, the difficulty of sleeping on the streets is so high during the winter in places like Minneapolis that unsheltered homelessness is extremely rare. However, there is wide variation in rates of unsheltered homelessness in warmer places. For example, Orlando, Las Vegas, and San Francisco all have average January temperatures of between 50 and 60 degrees Fahrenheit. But their rates of unsheltered homelessness are 2, 19 and 60 per 10,000 people respectively. In general, CoCs in California have higher rates of unsheltered homelessness than CoCs in Florida, despite similar January temperatures. It is clear that warm climates enable, but do not guarantee, high rates of unsheltered homelessness. Thus, factors beyond climate help determine rates of unsheltered homelessness in warm places. (Emphasis added.)

Here are some other weather or climate factors that matter when you are homeless:
  • How much precipitation do you get?
  • What is the diurnal temperature variation?
  • What is the nighttime low? Specifically, how often do you see freezing nighttime temps?
  • Are there other aspects of local weather that will cause physical distress, such as severe wind, dryness or frequent hail?
So let's look a bit at the three cities they listed in their example: Orlando, Las Vegas and San Francisco. Off the top of my head, without looking up any data whatsoever, I can tell you Orlando gets tons more rain than either Las Vegas or San Francisco.

Rain is a huge problem when you are homeless. You don't just want to be someplace warm enough to not freeze to death. If you are sleeping outdoors most of the time, you ideally want to be someplace both warm and dry.

But let's give some actual figures for annual rainfall for these three cities: So that brings up a new question: Why would San Francisco have more than 3 times as many homeless people per capita as Las Vegas when it gets 5.66 times as much rain?

Again, without looking up anything at all, I can tell you that Las Vegas is in a desert and far from the coast. As such, it will have much larger diurnal temperature variations than either Orlando or San Francisco. Coastal climates and damp climates have less diurnal temperature variation.

I used to live in the High Desert of California, not hugely far from Las Vegas. The large diurnal temperature variation is challenging to deal with even when you have a cushy, upper middle class life.

I was in a 2100 sqft house, the largest home I have ever lived in, and we had two cars during that time. It was the most upper class lifestyle I have ever had.

I kept a jacket in the trunk of my car in case I left during the day and came home after dark. The temperature difference from day to night could, at times, go from too hot for comfort to literally freezing and a forty or fifty degree (Fahrenheit) swing wasn't crazy weird.

That's a really big problem if you are homeless, especially if you are out on the street rather than sleeping in your car. If diurnal temperature variation is small, you dress for hot weather in summer or cold weather in winter and you are more or less good round-the-clock. But trying to carry extra warm clothes while it's hot so you won't die of hypothermia later that same day is a big logistical and practical burden.

Additionally, deserts are very dry, which puts stress on your system at any temperature. Plus, Las Vegas is also in the High Desert. It is at 2001 feet above sea level. Elevation is another factor that can stress your system and make weather hard to handle.

On top of that, average daytime highs for three months of the year are in the triple digits in Las Vegas. You aren't in much danger of freezing to death, but you are in danger of dying from heat prostration.

So let's update our preferred climate from warm and dry to temperate and not too rainy. Because too much heat is just as problematic as too little.

That isn't to say that I fundamentally disagree with the idea that there are other factors beyond climate that influence local rates of unsheltered homelessness. But the single weather metric used to examine the three cities cited doesn't adequately address the factor of weather or climate by any stretch of the imagination.

A much better example of the fact that weather doesn't explain it all is the high rates of homelessness in the rainy state of Washington.

I currently live in Washington state. I moved here from California to get myself back into housing.

I don't fully understand the phenomenon or what all factors are at play, but I've been here long enough to feel like social or cultural factors are part of it.

I can tell you that even local homeless shelters don't understand what matters to actual homeless people. There is a local policy of opening additional emergency shelters on nights with freezing temperatures.

On the surface that sounds like a good policy, but it's really very inadequate to the needs of the homeless people here locally because we get a lot of storms. The worst of them are mostly during the winter and this fact is not adequately addressed by that policy.

I have personally overheard a homeless person very upset over the fact that a big storm was coming, but the emergency winter shelters would not be opening because it was coming up from Hawaii instead of down from the Bering Sea.

So it was going to be well above freezing and local policy doesn't seem to think it's a big problem to be outdoors during a big storm. It also doesn't account for the fact that if you are soaking wet and it's not actually warm or hot, you can die of hypothermia in relatively mild temperatures:

Hypothermia can occur even with prolonged, unprotected exposure to relatively mild ambient temperatures of 60 to 65 degrees. Add wind-chill and wet (from the weather or perspiration) and an unsuspecting worker can succumb.

Here are some of the sites I looked at in the course of putting together this information (some of which are also linked within the page, above, though not all links above are included below):

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