July 2012: hottest month in U.S. history

By: Dr. Jeff Masters , 7:16 PM GMT on August 10, 2012

During the 1930s, a series of epic heat waves gripped the U.S., drying up the soil in an unprecedented drought that brought about the great Dust Bowl. The most intense heat hit during July 1936, which set a record for hottest month in U.S. history that stood for 76 years. That iconic record has now fallen, bested by 0.2°F during July 2012, which is now the hottest month in U.S. history, said NOAA's National Climatic Data Center (NCDC) this week. So far in 2012, we've had the warmest March on record, 3rd warmest April, 2nd warmest May, and warmest July. These remarkably warm months have helped push temperatures in the contiguous U.S. to the warmest on record for the year-to-date period of January - July, and for the 12-month period August 2011 - July 2012. Twenty-four states were record warm for that 12-month period, and an additional twenty states were top-ten warm. The past fourteen months have featured America's 2nd warmest summer (in 2011), 4th warmest winter, and warmest spring. The summer of 2012 is on pace to be a top-five warmest summer on record, and could beat the summer of 1936 as the warmest summer in U.S. history.


Figure 1. When the temperature peaked at an all-time high of 108° in Minneapolis, Minnesota on July 14, 1936, the want-ad staff at the 'St. Paul Daily News' was provided with 400 pounds of ice and two electric fans to cool the air in the press room. Photo from the Minnesota Historical Society.


Figure 2. Year-to-date temperature, by month, for 2012 (red), compared to the other 117 years on record for the contiguous U.S., with the five ultimately warmest years (orange) and five ultimately coolest years (blue) noted. The 2012 data are still preliminary. The year-to-date period of January - July was the warmest on record by a huge margin--1.0°F. Image credit: NOAA/NCDC.


Figure 3. For the fourth consecutive month, a new U.S. record for hottest 12-month period was set in July 2012. Five of the top-ten warmest 12-month periods in the contiguous U.S. since 1895 have occurred since April 2011. Image credit: NOAA/NCDC.

Most extreme January - July period on record
NOAA's U.S. Climate Extremes Index (CEI), which tracks the percentage area of the contiguous U.S. experiencing top-10% and bottom-10% extremes in temperature, precipitation, and drought, was 46% during the year-to-date January - July period. This is the highest value since CEI record-keeping began in 1910, and more than twice the average value. Remarkably, 83% of the contiguous U.S. had maximum temperatures that were in the warmest 10% historically during the first seven months of 2012, and 74% of the U.S. of the U.S. had warm minimum temperatures in the top 10%. The percentage area of the U.S. experiencing top-10% drought conditions was 20%, which was the 16th greatest since 1910. Extremes in 1-day heavy precipitation events were the 24th greatest in the 103-year record.


Figure 4. NOAA's U.S. Climate Extremes Index (CEI) for January - July shows that 2012 has had the most extreme first seven months of the year on record, with 46% of the contiguous U.S. experiencing top-10% extreme weather.

Little change to the U.S. drought during the past week
The great U.S. drought of 2012 remained about the same size and intensity over the past week, said NOAA in their weekly U.S. Drought Monitor report issued Thursday, August 9. The area of the contiguous U.S. covered by drought dropped slightly, from 63% to 62%, and the area covered by severe or greater drought stayed constant at 46%. The area of the country in the worst drought categories (extreme to exceptional drought) doubled from 10 percent last month to 22 percent this month. The extreme dryness and excessive heat devastated crops and livestock from the Great Plains to Midwest. During July, the area of the U.S. covered by moderate or greater drought was 57%, ranking as the 5th largest drought in U.S. history:

1) Jul 1934, 80%
2) Dec 1939, 60%
3) Jul 1954, 60%
4) Dec 1956, 58%
5) Jul 2012, 57%



Video 1. This is Not Cool: Peter Sinclair's July 2012 video from the Yale Forum on Climate Change and the Media couples historical footage with contemporary clips and news segments. In one of the latter, for instance, NBC anchor Brian Williams opens the network’s flagship news program with the words: “It’s now official. We are living in one of the worst droughts of the past 100 years.” NASA scientist James Hansen is featured testifying about risks of “extreme droughts” in the nation’s breadbasket, and I'm featured in a few clips talking about the drought of 2012.

I'll have a new post by noon Saturday.

Wunderground's weather historian Christopher C. Burt has a post looking back at the great Heat Wave of July 1936.

Jeff Masters


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1445 - 1395

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35Blog Index

Time: 12:21:30Z
Coordinates: 13.1667N 57.8667W
Acft. Static Air Press: 977.0 mb (~ 28.85 inHg)
Acft. Geopotential Hgt: 309 meters (~ 1,014 feet)
Extrap. Sfc. Press: 1012.1 mb (~ 29.89 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 267° at 8 knots (From the W at ~ 9.2 mph)
Air Temp: 23.0°C* (~ 73.4°F*)
Dew Pt: 23.0°C* (~ 73.4°F*)
Peak (10s) Flt. Lvl. Wind: 9 knots (~ 10.3 mph)
SFMR Peak (10s) Sfc. Wind: 5 knots (~ 5.8 mph)
SFMR Rain Rate: 3 mm/hr (~ 0.12 in/hr)
(*) Denotes suspect data

WE still got a TD.
Member Since: December 31, 1969 Posts: Comments:
Morning...Another Ernesto situation.Looks better than it was as a tropical entity when it's a weak storm/tropical wave?.The hell is up with these storms?.Still waiting for Isaac.It seeems Gordon will come from 93L after all.
Member Since: December 31, 1969 Posts: Comments:
1443. SLU
hmm ... 13.3n 57.9w?
Member Since: Posts: Comments:
right people we have the circulation and a whole crap load of W wind TD 7 is still here and is not a wave at at all
Member Since: December 31, 1969 Posts: Comments:
W, S and SSW winds found near 13 N and 58 W
Member Since: Posts: Comments:
1440. SLU
Quoting unknowncomic:
Over the years seems like the Atlantic never gets going till the East Pacific shuts down. Maybe related to MJO?


mainly
Member Since: Posts: Comments:
Quoting gordydunnot:
Hey Pdoug they grow any crops around you up there.



Yes. North part of the county, corn, cotton, and weed.
Member Since: Posts: Comments:
1438. SLU
Quoting gordydunnot:
Just in from the HH,They are playing the song another one bite's the dust over plane intercom. Wonder what that means?


lol
Member Since: Posts: Comments:
Hey Pdoug they grow any crops around you up there.
Member Since: Posts: Comments:
Quoting VR46L:
Hmm looks a little better this morning than I expected



and rather good in rainbow



There is rotation at the 925 and 850 mb levels but so far no indication of a closed surface low from the HH obs
Member Since: Posts: Comments:
We had rain again this morning here in Panama City. It has to have rained for the past month straight now. The swamp is trying to reclaim what used to be my yard. The mosquitoes are flourishing, though.
Member Since: Posts: Comments:
Quoting CANTBELIEVEIT:
Once again it looks like i was 100% correct in saying 4 days ago that there will be no gordon and it will go way south and fall apart and the other storm will fizzle and be a fishie remember post 1032 4 days ago when i said all that :)


Respectfully, that was a 50/50 lucky guess..........Are you actually trying to take credit for a random prediction, 4 days out, that could have gone either way just because you were on the lucky side of the guess?
Member Since: Posts: Comments:
1433. icmoore
Quoting PensacolaDoug:


Since our big dump of rain back on Sat June 9th, it has rained almost everyday. Probably 50 days out of the last 60 is my guess.


I thought so. Every morning I look at the radar I see rain up there!
Member Since: Posts: Comments:
Back further South and still all NE winds and pressure 1011 mbs
Member Since: Posts: Comments:
Over the years seems like the Atlantic never gets going till the East Pacific shuts down. Maybe related to MJO?
Member Since: Posts: Comments:
Looking at the Atlantic visible 93L has got to be the largest nothing I have ever seen.
















Member Since: Posts: Comments:
1429. VR46L
Hmm looks a little better this morning than I expected



and rather good in rainbow

Member Since: December 31, 1969 Posts: Comments:
Quoting PcolaSurf182:



Looks like another soggy day here in Pensacola. What a change from last summer right?


Since our big dump of rain back on Sat June 9th, it has rained almost everyday. Probably 50 days out of the last 60 is my guess.
Member Since: Posts: Comments:
Quoting stormpetrol:
I personally think the center is around 12.5N/56.7W a bit more south and east than the official estimate

I think it is S of NHC estimated COC HH just passes it however missed the COC to the hunters's S plane is flying back south to investigate

Quoting gordydunnot:
Just in from the HH,They are playing the song another one bite's the dust over plane intercom. Wonder what that means?
Quoting SLU:
- no pressure minimum near the estimated center

- no west winds south of the "center"

- no deep convection and spiral banding

- rapid 25mph westward motion

Sounds like a blob rather than a tropical cyclone....

you two hold you horses wait
Member Since: December 31, 1969 Posts: Comments:
Good Morning. Looking more, from the NHC advisory and subject to what the Hunters find this am, that we might have to wait a little longer for Gordon. Doesn't bode well for TD7 that it is still booking along, like Ernesto, at 24 mph. Might be very hard to find a well defined circulation at the surface.
Member Since: Posts: Comments:
ok by the looks of it the HH just missed the COC to its S HH needs to fly S

Quoting atmosweather:
AT 800 AM AST...1200 UTC...THE CENTER OF TROPICAL DEPRESSION SEVEN
WAS ESTIMATED NEAR LATITUDE 14.0 NORTH...LONGITUDE 57.5 WEST.
HOWEVER...PRELIMINARY DATA FROM THE HURRICANE HUNTER AIRCRAFT
INDICATE THAT THE DEPRESSION COULD BE DEGENERATING INTO A TROPICAL
WAVE.

That is BULL HH hasen't even gone into the COC yet they just missed to its S

and they are estimating the location of the COC

and the HH are now flying S to look for that COC
Member Since: December 31, 1969 Posts: Comments:
Intreasting veiw of uv radiation

Member Since: Posts: Comments:
Another page of NE winds from the HH
Member Since: Posts: Comments:
1422. SLU
- no pressure minimum near the estimated center

- no west winds south of the "center"

- no deep convection and spiral banding

- rapid 25mph westward motion

Sounds like a blob rather than a tropical cyclone....
Member Since: Posts: Comments:
I personally think the center is around 12.5N/56.7W a bit more south and east than the official estimate
Member Since: December 31, 1969 Posts: Comments:
Just in from the HH,They are playing the song another one bite's the dust over plane intercom. Wonder what that means?
Member Since: Posts: Comments:
Quoting Abacosurf:
Thanks Kman. Any thoughts on the system over you. Nam develops something out of it once in the gulf.


The weather in the NW Caribbean is primarily being caused by diffluence on the SE and East of a ULL. There is nothing of any concern going on at the surface in terms of tropical development at this time

See WV loop here of the ULL
Member Since: Posts: Comments:
Quoting Abacosurf:
Just south of west Cuba looks interesting this morning. looks mostly mid to upper level. Whats the wind direction in Cayman this morning?


here its just about dead calm but obs from work for 6am says ESE other obs say SE ESE one says NE but mostly ESE and it is expected from a passing tropical wave but wave is in the GOM now
Member Since: December 31, 1969 Posts: Comments:
Quoting kmanislander:


Light at 3 MPH out of the SE.

1.94 inches of rain since midnight
Thanks Kman. Any thoughts on the system over you. Nam develops something out of it once in the gulf.
Member Since: Posts: Comments:
1010.8 mbs but all NE winds in the next swath
Member Since: Posts: Comments:
Latest set of HH obs show mostly NE winds and no winds stronger than 24mph.
Member Since: Posts: Comments:
Quoting GeorgiaStormz:


true...I dont think there is a closed COC, but recon hasnt gone to the center yet have they?


If there is a center they have not found it so far.
Member Since: Posts: Comments:
At this time, the 2012 season is very boring, nothing very serious on the Atlantic ocean...only tropical waves or tropical depression... where are the major H? Already in vacations lolll
Member Since: Posts: Comments:
AT 800 AM AST...1200 UTC...THE CENTER OF TROPICAL DEPRESSION SEVEN
WAS ESTIMATED NEAR LATITUDE 14.0 NORTH...LONGITUDE 57.5 WEST.
HOWEVER...PRELIMINARY DATA FROM THE HURRICANE HUNTER AIRCRAFT
INDICATE THAT THE DEPRESSION COULD BE DEGENERATING INTO A TROPICAL
WAVE.
Member Since: Posts: Comments:
Quoting Abacosurf:
Just south of west Cuba looks interesting this morning. looks mostly mid to upper level. Whats the wind direction in Cayman this morning?



Light at 3 MPH out of the SE.

1.94 inches of rain since midnight
Member Since: Posts: Comments:
From the 8AM advisory:

PRELIMINARY DATA FROM THE HURRICANE HUNTER AIRCRAFT
INDICATE THAT THE DEPRESSION COULD BE DEGENERATING INTO A TROPICAL
WAVE
Member Since: Posts: Comments:
Long time lurker here figured i'd post up.


...TROPICAL DEPRESSION APPROACHING THE WINDWARD ISLANDS...HURRICANE HUNTER AIRCRAFT CURRENTLY INVESTIGATING THE SYSTEM...

8:00 AM AST Sat Aug 11
Location: 14.0N 57.5W
Moving: W at 24 mph
Min pressure: 1008 mb
Max sustained: 35 mph
Member Since: Posts: Comments:
And nothing on the next update either. Seems to have degenerated for the time being...doesn't mean we can write the system off for good. I want to see how much of its energy it can hold onto as it moves into the Caribbean.
Member Since: Posts: Comments:
Quoting rmdjoe1954:
Scats are a very reliable analytical tool. While I agree that HH obs are the best you should not simply dismiss the Oscat pass from last night because it does not support your own conclusions.


true...I dont think there is a closed COC, but recon hasnt gone to the center yet have they?
Member Since: Posts: Comments:
Quoting HondosGirl:
.....and the Thunder Rolls! Waking up early this Saturday to continuous thunder and a constantly flashing sky. Light rain and much cooler temperatures have also arrived here in Northwest Florida.



Looks like another soggy day here in Pensacola. What a change from last summer right?
Member Since: Posts: Comments:
Quoting atmosweather:
The latest round of obs shows nothing in the way of a closed circulation, but its possible it may be located further to the S than the advisory positions, thus they are still checking. Next update will be the telling one.

maybe time will tell

Quoting SLU:
It be shocked if the recon finds a closed low. There's no evidence of it in the satellite imagery nor surface observations
there looks to be on Sat but still too early to tell yet by Sats not enough visible images came in yet
Member Since: December 31, 1969 Posts: Comments:
Just south of west Cuba looks interesting this morning. looks mostly mid to upper level. Whats the wind direction in Cayman this morning?

Member Since: Posts: Comments:
Quoting wunderkidcayman:

I geuss thats true

you last bit I did not say I dismiss it cause deon't support what I say I never said that


on another note if HH find a good amount of W wind (more than ernesto had at this location) then its is doing better than Ernesto



I never said you did but that was my conclusion as to why you were so dismissive of the Oscat pass. I bet if it had shown a closed low you would have jumped on that as showing that TD7 was still alive and well.

My point is that you need to be more objective in relation to what is or was actually out there from the observation tools available.
Member Since: Posts: Comments:
Still all East winds and no pressure under 1011mbs so far
Member Since: Posts: Comments:
Quoting kmanislander:


Scats are a very reliable analytical tool. While I agree that HH obs are the best you should not simply dismiss the Osact pass from last night simply because it does not support your own conclusions

I geuss thats true

you last bit I did not say I dismiss it cause deon't support what I say I never said that


on another note if HH find a good amount of W wind (more than ernesto had at this location) then its is doing better than Ernesto

Member Since: December 31, 1969 Posts: Comments:
1396. SLU
It be shocked if the recon finds a closed low. There's no evidence of it in the satellite imagery nor surface observations
Member Since: Posts: Comments:
The latest round of obs shows nothing in the way of a closed circulation, but its possible it may be located further to the S than the advisory positions, thus they are still checking. Next update will be the telling one.
Member Since: Posts: Comments:

Viewing: 1445 - 1395

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35Blog Index

Top of Page

Category 6™

About

Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather