Weather Historian C.C. Burt on July’s extreme Temps Worldwide

Recap of record-breaking heat this past July in the U.S. + Asian heat record?

Published: 8:52 PM GMT on August 02, 2012

Recap of record-breaking heat this past July in the U.S. Possible new heat record for Asia observed

Although the final ranking of this past July will not be released by the NCDC until around August 7th, it would appear that the month will almost certainly rank in the top five warmest July’s on record since official records began in 1895 (and perhaps even in the top three). Here is a summary of some of the more notable records set so far this summer. In addition, I have included a brief message concerning a potential new heat record for the continent of Asia.

Although this map is specifically for July 5th, it represents the overall pattern that most of the country has been stuck with for almost the entire month of July 2012.

Warmest Single Month on Record (any month)

Preliminary data from the NCDC reports that 4,313 record daily highs, 293 monthly record highs, and 171 all-time record highs were observed this past July (among the approximately 5,500 various official weather sites across the nation). Many of these sites, however, have limited periods of record that do not extend back to the 1930s when the country’s greatest heat waves occurred.

The WU extremes U.S. database follows 298 significant sites in the country, all of which have long periods of record (almost all back to the 19th century) and represent a mosaic of evenly spaced geographic locations representing all the climate zones in the country. About 90% of the country’s population resides within a 50-mile radius of one of these sites. From this list the following cities recorded their single-warmest month on record:

The following cities from the WU extremes database have broken or tied their all-time absolute maximum temperatures on record (including this past June):

Comparing this July to July of 2011

Perhaps what is truly astonishing is that this July (2012) piggybacks upon the equally torrid summer (and July) of 2011. Although, back-to-back record-breaking hot summers are not unheard of (summers in the 1930s and 1950s come to mind) it is nevertheless disconcerting.

Here is a comparison of extremes reached in July 2012 versus July 2011. Also, to put this in context, is a comparison to July of 1936, still almost certainly the hottest July (and single month) in U.S. records. Again this list includes only the 298 cities in the WU database:

This table shows the number of cities (out of 298 in all) that recorded their respective single-warmest month on record and absolute maximum temperature on record for the June-July month timeframes in 2012, 2011, and 1936.

Honorable Mentions

Other major cities came VERY close to breaking their all-time warmest single month on record including Washington, D.C. (National Airport) with a July average of 84.0° just shy of the record 84.5° set last July (2011). The Dulles Airport location was also close with 80.6° vs. 81.0° in July 2011. Raleigh, North Carolina averaged 83.5°, shy of their record 84.1° set in August 2007. Chicago, Illinois official site at O’Hare Airport registered an average of 81.1° just short of the 81.3° record set in July 1995. However, the Chicago Midway Airport location, which is more representative of the city itself and also has a much longer period of record (POR) than O’Hare, smashed its all-time warmest month record with an average of 82.6° versus 81.3° in July 1955. Louisville, Kentucky experienced its warmest ever July with an average of 84.5°, but fell short of its single-hottest-month record of 85.0° set in August 2007. Madison, Wisconsin (home of my alma matter!) has just endured its 2nd hottest month on record with a 79.4° average, just short of the record 79.8° set way back in July 1901.

Of course, this is just a short list of the many amazing ‘heat feats’ this past July. I should also mention a couple of the many endurance records that have been set:

Fort Wayne, Indiana: 22 consecutive days above 90° ending on July 18 (old record was 14).

St. Louis, Missouri: 11 days above 105° (old record was 10 in 1934). Also, St. Louis tied its warmest night on record with a low of 86° on July 25th (also occurred on July 24, 1901).

New Asian Heat Record Set?

On a similar topic but different continent, I have late word in from temperature detective Maximiliano Herrera that on July 31st a temperature of 53.6°C (128.5°F) was measured at Sulaibya (Sulaibiya), Kuwait. This location is on the outskirts of Kuwait city and is a water treatment facility.

A Google map image of the location in Kuwait of Sulaibya. Google Earth image.

Although the Kuwaiti meteorological office must make a final determination towards the records validity, a local expert, Dr. Juergen Herrmann (Team Leader Meteorology Specialists, Stanley Consultants, Int’l based in Kuwait) has the following comments in response to a request from Max for additional details:

“We are aware of the new record temperatures. There is no reason why these should not be considered records. Everything is technically OK at the station. You may have detected that the same day we had quiet an amount of other stations in the “vicinity” also have high to record temperatures.

The microclimate at this agro-station is surrounded by high sand dunes and thus has very low wind speeds at 2m height [which] results in a local heat island. Therefore I would not consider this temperature representative for an area bigger than 0.5×0.5km. The next station to Sulaibiya which gives a proper picture for the surrounding area is Jahra – 40586 – and had maximum temperature at the same day of 51.8 deg C. To my best guess this verifies both stations are working properly. Especially as a number of other stations also had really high temperatures that day due to generally low wind speeds with nearly no dust reducing the incoming solar radiation.”

If verified, this would surpass the 53.5°C (128.3°F) measured at Moen Jo-Daro, Pakistan on May 26, 2010. The reading of 54°C (129.2°F) from Tirat Tsvi, Israel on June 22, 1942 remains under suspicion. The Israeli Met. Office pursued an investigation of the record this past year (prompted by an enquiry from the WMO and myself) and concluded it was valid. However, they have refused to make public the details leading to their conclusions, so until they do so the record remains suspect.

KUDOS: Maximiliano Herrera for uncovering yet another possible world record temperature.

Christopher C. Burt
Weather Historian


Jeff Masters on Heat, TS Ernesto, etc.

Ernesto hit the Windward Islands; 128.5°F in Kuwait
Posted by: Dr. Jeff Masters, 1:49 PM GMT on August 03, 2012 +17

Tropical Storm Ernesto lashed the Windward Islands with strong winds and heavy rain early this morning, as it passed over St. Lucia near 7 am AST. Ernesto brought sustained winds of 43 mph to Barbados at 7 am AST, and sustained winds of 41 mph, gusting to 63 mph to St. Lucia at 6:15 am AST. Ernesto looks moderately well-organized on Martinique radar, with spiral bands to the north and south feeding into an echo-free center. Ernesto is beginning to show more organization on visible satellite loops, with the very limited heavy thunderstorm activity near its center now expanding, spiral banding increasing, and an upper-level outflow channel developing to the north. Ernesto is fighting moderate wind shear of 10 – 20 knots, and water vapor satellite loops show a large area of dry air to the west. Strong upper level winds from the west are driving this dry air into the core of the storm, disrupting it. It appears, though, that Ernesto has fended off the most serious challenges to its survival, as the pressure has fallen to 1002 mb, and the storm’s appearance on radar and satellite is gradually improving. The latest 7:30 am center report from the Hurricane Hunters also indicated that Ernesto was beginning to build an eyewall.

Figure 1. Radar image of Ernesto at 9:15 am EDT August 3, 2012. Image credit: Meteo France.

Figure 2. Morning satellite image of Ernesto.

Forecast for Ernesto
Ernesto’s survival into today means that the storm now potentially poses a formidable threat to the Western Caribbean. Wind shear is expected to drop to the low range, 5 – 10 knots, later today, and remain low for the next five days, according to the 8 am EDT run of the SHIPS model. With the storm entering a moister environment with increasing heat energy in the ocean, the official NHC forecast of Ernesto reaching hurricane strength by early Monday morning near Jamaica is a reasonable one. The reliable computer models predict a west to west-northwest motion through the Caribbean, with the storm’s heavy rains staying south of Puerto Rico and the Dominican Republic. The more southerly path predicted by the usually reliable ECMWF model, which brings Ernesto to a landfall in Belize on Wednesday, is being weighted less heavily by NHC, since they are assuming Ernesto will stay stronger than the ECMWF model is forecasting. Once Ernesto enters the Central Caribbean on Sunday, the storm’s outer spiral bands will likely cause flooding problems in Southwest Haiti, Jamaica, and the Cayman Islands. Of the major dynamical models NHC uses operationally–the ECMWF, GFS, NOGAPS, UKMET, GFDL, and HWRF–none clearly show Ernesto reaching hurricane strength in the Caribbean. However, some of the best statistical models, such as the LGEM and SHIPS, do show Ernesto becoming a hurricane in the Caribbean. By Monday, a trough of low pressure passing to the storm’s north may be capable of turning Ernesto more to the northwest, resulting in the storm entering the Gulf of Mexico by the middle of next week.

New African tropical disturbance 90L
A strong tropical wave is located just off the coast of Africa, about 175 miles south of the Cape Verde Islands. This disturbance, designated Invest 90L by NHC Friday morning, is headed west-northwest at 10 – 15 mph. Wind shear is a high 20 – 30 knots over 90L, but is expected to drop, and water temperatures are warm enough to support development. NHC gave 90L a 30% chance of developing into a tropical depression by Sunday morning in their 8 am Friday Tropical Weather Outlook.

Kuwait hits 53.6°C (128.5°F): 2nd hottest temperature in Asian history
An extraordinary high temperature of 53.6°C (128.5°F) was recorded in Sulaibya, Kuwait on July 31, the hottest temperature in Kuwait’s history, and the 2nd hottest temperature ever measured in Asia. According to weather records researcher Maximiliano Herrera, Sulaibya is in a location well-suited for recording extreme high temperatures, since high sand dunes surround the site, keeping the wind low and hampering sea breezes from cooling the city. Most record books list the 54°C (129.2°F) recorded on 21 June 1942 in Tirat Zvi Israel as the site of Asia’s all-time maximum temperature, but this record is disputed. The previous second warmest temperature in Asian history was set 53.5°C (128.3°F) at MohenjuDaro, Pakistan on May 26, 2010.

Extreme heat in Oklahoma
The most intense and widespread heat wave in Oklahoma since August, 1936 brought more than half of the state temperatures of 110° or higher for the second consecutive day on Thursday. The temperature at the Oklahoma City airport hit 112°, for the 2nd day in a row. These are the city’s 2nd highest temperatures since record keeping began in 1890. The only hotter day was August 11, 1936, when the temperature hit 113°. Thursday’s temperatures in Oklahoma were generally a degree or two cooler than Wednesday’s, with the hottest temperature reported a 116° reading from a location just south of Tulsa International Airport. The highest reading Thursday at any major airport was a 114° temperature at Tulsa Jones Airport. Oklahoma’s all-time state record is 120°, set in Tipton on June 27, 1994, and at three locations in 1936. Freedom, in the northwest part of the state, hit 121° on Wednesday, but this reading will need to be reviewed to see if the sensor was properly sited.

Jeff Masters