First Recorded Temperature In The Teens For September At International Falls, MN

[Mallow]

Really?

Yes really.

[Quixotic1]

Really? Here's what makes the news: "U.S. had warmest summer in 75 years". That's a very misleading headline. That's based off of a national average which is especially misleading this summer. Overall, in the lower 48 of the U.S. 36 states were cooler than summer of 2010, 1 was the same, & only 11 warmer. The average spiked up because of the record heat in Texas, N. Mexico, Oklahoma, Louisiana. Take those states out & it doesn't even come close to the WIDESPREAD heat of 2010.

It was a hot summer but headlines like that are very misleading. Do you think that would happen during the winter? I haven't seen one story or headline about the record cold or snow in parts of S. America a few weeks ago. Snow in some places for the first time in over 40 years...BUT a record heat wave in Russia makes the news. Last winter was very cold & snowy...lots of record snows in the U.S. but that did not receive near as much attention as anything related to warmth does.

So, one record low for one small town trumps:

Hottest summer ever for one state (Texas) and the second hottest summer ever for one state (Oklahoma). In terms of area affected, scale and persistence, the comparison is not even close.

[phil882]

Sure. But thanks to UHI, it's much harder for large cities to record record lows than smaller towns. Just the way it is.

Of course... so its no wonder you hear about more record highs being set in large cities than record lows. As long as you have an urban heat island that had caused an anthropogenic change in the temperature at a specific city, you will in fact tend to experience more record highs than record lows. Thus, the media attention on record highs is likely to be due to the fact that they occur more often in urban cities in comparison to record lows.

[tacoman25]

So, one record low for one small town trumps:

Hottest summer ever for one state (Texas) and the second hottest summer ever for one state (Oklahoma). In terms of area affected, scale and persistence, the comparison is not even close.

WA and OR just had their coldest April-June on record earlier this year...just saying.

[Quixotic1]

WA and OR just had their coldest April-June on record earlier this year...just saying.

Now, if WA and OR (or any of the "cold" states for that matter) had the coldest April - June on record for all of the states, then we got something.

[Quixotic1]

Of course... so its no wonder you hear about more record highs being set in large cities than record lows. As long as you have an urban heat island that had caused an anthropogenic change in the temperature at a specific city, you will in fact tend to experience more record highs than record lows. Thus, the media attention on record highs is likely to be due to the fact that they occur more often in urban cities in comparison to record lows.

I vaguely remember having this conversation over at EWX when the Russian heat wave was going on last year. Has there been a study comparing record setting temps in areas that haven't undergone urbanization since global temps have warmed?

[salbers]

As impressive as that is I bet it will not be a headline or even be mentioned by any national news outlet. Only records on the warm side make the news these days & not only make it but are mentioned over & over & over again.

I actually learned about this on a national news/weather show (Good Morning America)...

[BethesdaWX]

Sure. But thanks to UHI, it's much harder for large cities to record record lows than smaller towns. Just the way it is.

Well of course UHI is a heavy factor, but you can't deny a significant portion of the warming trend in big cities has been just that, a warming trend, not just an increase in UHI. The Irk-factor is a result of claimed causations to the underlying trend, not the trend itself.

Conspiracy theories aside.

[skierinvermont]

I vaguely remember having this conversation over at EWX when the Russian heat wave was going on last year. Has there been a study comparing record setting temps in areas that haven't undergone urbanization since global temps have warmed?

Yes.. record highs and record high lows much more common than the reverse in rural areas too.

[tacoman25]

Yes.. record highs and record high lows much more common than the reverse in rural areas too.

I would like to see a comprehensive study on this.

I do know that when I have compared urban sites with rural sites in several regions, the urban sites had a lot more record warm lows and a lot less record cold lows than their rural counterparts. So it definitely does make a difference.

[BethesdaWX]

I would like to see a comprehensive study on this.

I do know that when I have compared urban sites with rural sites in several regions, the urban sites had a lot more record warm lows and a lot less record cold lows than their rural counterparts. So it definitely does make a difference.

It does have an impact predominately at night, but another issue is station siting, peronsally I feel it might be a bigger issue than UHI as far as error-correction goes.

Earlier this yr a peer-reviewed study (Surfacestations.org) found that, in the US, a significant portion of stations were cited poorly. Though in the end there was NO impact on the temperature trend as a whole, as daytime & nighttime temps have been warming everywhere, the time of day the largest anomalies are occuring is important. Specific night-time records in Lager Cities just shouldn't be used to determine anything, though even rural stations are breaking more high temp records than low temp records for the time being.

Though in the SurfaceStations.org paper it was concluded that the warming trend at night was being significantly over-estimated, and the warming trend during the day was being significantly underestimated, which is (for me) by far the most important conclusion, exactly what I was looking for (and expecting).

[Quixotic1]

Yes.. record highs and record high lows much more common than the reverse in rural areas too.

Would love to see that. FWIW, that's what I would expect.

I would like to see a comprehensive study on this.

I do know that when I have compared urban sites with rural sites in several regions, the urban sites had a lot more record warm lows and a lot less record cold lows than their rural counterparts. So it definitely does make a difference.

I too would like to see a comprehensive study. It makes more sense that if temps are rising globally, then the rural areas would rise as well. At least we could rule out urbanization as a cause for warmer temps.

Question is: How would you pick your areas? Do you go on population remaining static or are other things considered such as an increase of man made surfaces such as concrete/asphalt/buildings etc?

[BethesdaWX]

Would love to see that. FWIW, that's what I would expect.

I too would like to see a comprehensive study. It makes more sense that if temps are rising globally, then the rural areas would rise as well. At least we could rule out urbanization as a cause for warmer temps.

Question is: How would you pick your areas? Do you go on population remaining static or are other things considered such as an increase of man made surfaces such as concrete/asphalt/buildings etc?

The entire globe won't warm/cool in sync, though I'd suggest using the HADCRUT3 dataset. Aside from the Arctic regions, the rest of the globe has been in a general flat-lining trend, (A statistically Insignificant cooling trend if you prefer that).

The reason for the warmer records continuing to fall is the fact that despite trends, the globe is still very warm and, on a regional basis, the temps can't be record breaking year-round.

Because of this a global mean Urban vs Rural is probably necessary due to natural variation on a regional scale.

[uncle W]

Would love to see that. FWIW, that's what I would expect.

I too would like to see a comprehensive study. It makes more sense that if temps are rising globally, then the rural areas would rise as well. At least we could rule out urbanization as a cause for warmer temps.

Question is: How would you pick your areas? Do you go on population remaining static or are other things considered such as an increase of man made surfaces such as concrete/asphalt/buildings etc?

if you look at NYC's average annual temperatures you will see a big rise in the average during the 1890's, 1930's and 1980's...Some or all of the difference in temperatures might be due to a growing heat island effect from the heavy development of Manhattan during those periods...Manhattan expanded greatly in the late 1900's...The industrial revolution came around the same time...The 1920's was another building boom with the Crysler Building and Empire State building completed in the early 1930's...The 70's boom brought the World Trade Center and many other skyscrapers...A study needs to be done on the building boom and the rise of average temperatures in NYC...

[tacoman25]

Would love to see that. FWIW, that's what I would expect.

I too would like to see a comprehensive study. It makes more sense that if temps are rising globally, then the rural areas would rise as well. At least we could rule out urbanization as a cause for warmer temps.

Question is: How would you pick your areas? Do you go on population remaining static or are other things considered such as an increase of man made surfaces such as concrete/asphalt/buildings etc?

This.

I have found that stations that remain in areas that are largely undeveloped/rural, cold low temp records are more easily broken and not as many warm low temp records are set. Granted, I haven't done a comprehensive study, just in a few areas. But the results have been fairly consistent.

[friedmators]

sort of related

http://www.cbc.ca/news/technology/story/2011/09/19/science-oceans-climate-change.html?cmp=googleeditorspick