What is the definition of extremely warm? Do you think that might make the graph a little more clear? And when was the last time it was 105 F in San Fran? I may tend to be a glass half full kind of person, but here is the graph of max summer temps for the US since 1895. https://www.ncdc.noaa.gov/cag/national/time-series/110/tmax/3/9/1895-201... Anyone see a trend? I don't. I see year to year variation and longer term (decades) where the trend is either up or down, but there is no evidence here for any warming. You certainly wouldn't buy a stock based on this chart. Now, if you select min temps from the drop down you will see a trend. But what is that trend based on? Well, if you look at areas like Phoenix that have grown & urbanized rapidly you will see a dramatic increase in the difference between min and max temps. Which is consistent with the urban heat island effect. Note that this article says that the difference in warming trend is consistent with what climate models --- but makes no attempt to state why there would be a difference or what these models say. If it's only an urban heat island effect then are we supposed to set our hair on fire over this? Note that for less urbanized states like Alabama and Georgia, the min temps aren't getting warmer. This seems to be a story without much to substance.

Another misleading article(in a series). What and where is the data behind those graphs? What does extremely warm mean? When was the last time it was 105 F in San Francisco? Go to the NOAA data site and look at the data for large cities... like Phoenix... it is very clear that this differential (if real and not an artifact of measurement issues) is due to urbanization. This type of reporting convinces no one, it just feeds the alarmists desire for apocalyptic climate scenarios.

What do the rich care? With their personal and corporate tax cuts, they can afford just to run even more more air conditioning in their homes, offices, limos and private jets. Their GOP lackeys are already working night and day to take away healthcare from those who cannot afford it, condemning thousands annually to sicken and die. So global warming will carry off more. Their lives are worthless anyway -- worth less than the lives of the rich.

Yes, nights are warming faster. And yes, heat stroke kills many many people. But to say this is dangerous is to vastly underestimate the ability of homo sapiens to adjust. When temperatures get warmer we have air conditioners -- look at Florida which, weatherwise, is totally inhospitable -- and we are nomadic and if one place is uncomfortable to us we move elsewhere. I like the science here but I dislike the apocalyptic tone.

Yet ANOTHER problem (global warming) we know about, but will refuse to do much about. Politics as usual will intrude. Could we be any dumber?

This article seems to cover all the bases right down to the "blacks and hispanics most affected." A few days ago the NYT found that blacks and hispanics in Miami suffer the most from climate change because they occupy the highest land least likely to flood (vs. the wealthy beach areas). Why is it suffering to occupy the best land? Because wealthy investors offer you lots of money for your property!! RACISM pure and simple. And BTW cold kills 17 times as many people worldwide as heat: https://www.treehugger.com/health/cold-deadlier-heat.html

Blame the GOP, constant deniers of global warming, who even now are busy getting rid of Obama's insufficient regulations. They are pro-big business to the point of peril. Do they not have children? Do they think money might insulate them? Do they think Exxon will suddenly swivel and find a solution to save us? Whatever they once were, they are now a party that will help put us all out of business.

Thank you. For people who don't want to believe things are changing, it is one of the many ways the change may be observed. This is not your mother and father's climate. The cumulative pace of change is relentless. People argue that there are ups and downs in the pattern, but anyone paying attention doesn't need a weatherperson to tell them that overall change is growing. These nighttime temperatures reflect a disturbing disappearance of cooling balance when it's not. Due to other changes from a melting Arctic (which have reduced the "Atlantic Meridional Overturning Cirulation (AMOC) - roughly equated to the Gulf Stream which keeps us warmer) the one cool patch on earth is in the north Atlantic, so we in the most populated part of the eastern United States and northwestern Europe are not heating as fast as the rest of the planet. Here's one of many graphics with a simple text that anyone can understand: https://www.vox.com/science-and-health/2017/8/1/16074956/global-warming-... "Global warming isn't a smooth process, and there are fluctuations from year to year due to internal variability (e.g., changes in the sun's intensity, volcanic eruptions, or shifts in the amount of heat stored in deeper layers of the ocean). But as we keep adding greenhouse gases to the atmosphere and keep trapping extra heat on Earth, that effect eventually dominates, pushing overall temperatures higher and higher. The spiral moves outward."

This is an excellent first take on a single kind of observation that must set in motion analysis of the implications, something the article does very well. I spent 21 days up on Mount Philo (State Park), Charlotte VT, just south of Burlington leaving there on 21 June. Back in Sweden where I listen to Vermont Public Radio's many streams off and on through the Swedish night I heard that report on Burlington VT highest nightly low ever, and it set me thinking. I focus on your excellent presentation of what we can call the "air conditioner" problem. Night-time temperatures above x mean greater demand for air cooling during the night. As you note, if the cooling is done by conventional air conditioners running on electricity generated by fossil fuels, then the greenhouse gas problem enters into the picture, the "equation". But if the cooling is done by, for example, an air-air or air-water heat pump running on non-fossil fuel electricity then “no problem”, so to speak. (I write this from a home with such a system, common here) Yes, I know that a one-off in Burlington has no climate-change consequence, but if this comment could get a few Vermonters to finally realize that they could start a make-Vermont-Sweden movement by switching from natural gas to heat pumps, who knows where this might lead. Bernie Sanders, my make America Sweden hero, talked at a heat-pump day in Randolph Center, VT, when I was there. Listen to Bernie! Only-NeverInSweden.blogspot.com Citizen US SE

So often the missing component of any discussion about continuing and unabated global warming is continually increasing human populations. And more people in what are said to be undeveloped parts of the world wanting the items which require high amounts of energy which we have come to associate with good, Western world style of living. Human populations which surpassed 7 billion of us only a few years ago is now estimated with projections to be in the 10-11 billion range by the end of the century, possibly sooner. I read an article in the past year which, after the math was done, was that for each woman of child bearing age to limit herself to no more than two children, and preferably to one child, will over the long term have the most significant and marked effect on our planet and its livability. It should not be ignored that other species suffer as much or more than we do, many either reaching the point of extinction due to the expansion of human habitat, especially in those areas where fertility rates are persistently high, hunting and sheer ignorance. Here in the Puget Sound area with an anticipated 7 fold increase in shipping of fossil fuels coming by way of our waters, one of our beloved species, killer whales, are sadly calving fewer offspring each year, and may well become extinct, a possibility which likely seemed impossible 100 years ago. http://www.worldometers.info/world-population/

This is not a surprise. When the sun beats down (near daytime highs) heat is carried up by rising columns of air. Greenhouse gases have little effect on this, so we aren't getting more record highs. At night, when there are lows, heat is carried up by radiation, so increasing greenhouse gases make lows warmer. This was shown quantitatively in a recent paper by J. Finkel in the International Journal of Climatology. But this is not harmful. People are affected by the highest, most stressful, temperatures. Our bodies don't retain daytime heat until night (though it may feel that way, psychologically, and our buildings do cool off at night). We maintain temperature homeostasis minute by minute.

Our earth's natural air conditioner, the sea ice at the arctic circle, has melted away. The polar, white ice cap deflected the sun's rays. Now it is being absorbed directly into the darker seas. The future is not what it used to be. Not only more crowded but much, much hotter, everywhere.

For those who eagerly look forward to fresh, locally grown, summer tomatoes warm nights mean the tomato plants won't set fruit. They need nights under 70. Our fresh tomato season in Texas, sadly, is already over.

Isn't this pattern what one would expect from urban heat island bias in the record? Are the stated numbers adjusted for urbanization of station location over the past century?

I find the meaning of the charts labeled "Extremely warm nighttime lows" and "Extremely warm daytime highs" to be extremely confusing. Data that varies as randomly as this data does is rarely useful in understanding what is going on.

I take it that climate change deniers and skeptics don't live near anyplace where the "heat island effect" can be felt. Would that be a safe assumption? They just run their air conditioners as usual (when they're not standing in the shade at the golf course), and bemoan that Scott Pruitt was mistreated by the media...

Sure would be nice if information like this resulted in more than just hand wringing and shrugs.

Deadly consequences of increasing temperatures are usually reported with respect to communities of solely human animals ("people"); whereas effects upon non-human animal communities ("animals") are generally restricted to the Science section. As our biosphere declines in health and diversity, we should expand our perspective beyond anthropocentrism - and fast.

The models have been predicting this exact thing for a long time.

when i became crippled 31 years ago i also lost my talent for thriving in hot weather. a noted biofeedback doctor looked at me in disbelief one day when i arrived at my appointment - he said i never should have been out, and that i have so much nerve damage that i'd become a human barometer. add that little hurricane now well offshore up here...pressure changes, temp variances of more than 10-15 degrees. i thought i was being a wuss if i didn't complete my lists........get used to doing things when you can, people, and not when you want to.

The two bar graphs are interesting. The daytime graph seems to show a cyclic component contributing to modern warming with a period of around 60 years, which is suggestively similar to the Atlantic Multi-decadal Oscillation. The nighttime graph could be interpreted as the influence of population growth and urbanization superimposed on AGW. Without knowing exactly what datasets are involved it's hard to say.

Fake news! Based on data.

Nights are getting warmer. However, it's nice to see idiots like our elected leaders fighting over border walls. Humanity is doomed.

I've been talking about night time temperatures for years now. I clearly recall that we used to need sweaters at night at times in the summer, especially on the beach. Air conditioning was also used more rarely but now it seems we need it all summer. It's depressing and worrying and when you can well remember it being so different and so normal not that long ago, it feels like we are strangers in a strange, hot, and scary land. It would help some to do away with our pointless daylight saving time so the sun would set one hour earlier.

The "heat island" effect is dramatic in Southern California. It used to be that fog would form and linger in large areas of open land near the coast and often linger most of the day all summer long. Now that open land is essentially gone, and we get hotter weather year round. Land needs to breathe.

Wouldn't warm winter nights be beneficial in places like International Falls, MN? 33 % of the earth surface is seasonally frozen and 12 % is frozen year round, what about the effect there? Climate change research is all doom and gloom, do the funding sources require dire conclusions and scary headlines! Maybe the seniors will start to move to colder states for retirement instead of moving to Florida or Arizona. Better start buying real estate in Canadian Taiga before the crowds reach there.

Meanwhile, per capita CO2 emissions in the United States have dropped to the levels of the late 1990's. The culprits in increased CO2 are China, India, Indonesia and the entire continent of Africa, to name a few. Why? Because they want all the good stuff (cars, AC, reliable electricity, refrigerators) that we have. And there is nothing we can do to discourage their governments from providing the good stuff.