From NOAA/NCDC, something interesting: a new map showing when to expect hottest days of the year and where. The long thin line on the west coast is interesting because that is where the bulk of the population of each state lives and one might think that has something to do with it, but it is actually related to the marine layer.
Mercury Rising: When to Expect the “Warmest Day of the Year”
Following the first official day of summer, many areas in the United States are approaching their highest temperatures for the year. To give you a better idea of the warmest time of year for your area, NCDC has created a new “Warmest Day of the Year” map for the contiguous United States. The map is derived from the 1981–2010 U.S. Climate Normals, NCDC’s 30-year averages of climatological variables including the average high temperature for every day. From these values scientists can identify which day of the year, on average, has the highest maximum temperature, referred to here as the “warmest day.”
Although the amount of solar radiation reaching the earth peaked at the summer solstice on June 21 in the Northern Hemisphere, temperatures for most of the United States tend to keep increasing into July. The temperature increase after the solstice occurs because the rate of heat input from the sun during the day continues to be greater than the cooling at night for several weeks, until temperatures start to descend in late July and early August.
But, this isn’t the case everywhere! The “Warmest Day of the Year” map shows just how variable the climate of the United States can be. For instance, the June values in New Mexico and Arizona reflect the North American Monsoon, a period of increased rainfall affecting the Southwest United States. Because these areas tend to be cloudier and wetter from July through September, the temperature is highest on average in June. Similarly, the persistence of the marine layer along the Pacific Coast leads to cool temperatures in early summer with the warmest days on average later in the season.
Temperature Normals are important indicators that are used in forecasting and monitoring by many U.S. economic sectors. Knowing the probability of high temperatures can help energy companies to prepare for rising electricity demand and farmers to monitor heat-sensitive crops. They are also useful planning tools for the healthcare, construction, and tourism industries. You may want to check the Normals before planning your next event or vacation.
While the map shows warmest days of the year on average throughout the United States, this year’s actual conditions may vary widely based on weather and climate patterns.
Source: http://www.ncdc.noaa.gov/news/mercury-rising-when-expect-warmest-day-year
h/t to Tom Peterson
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I don’t even have to look. I despise hot, humid weather but somehow wound up living in NJ where every summer is 3 months of interminable mugginess. My birthday happens to fall on July 18th and it never fails…hottest day of the year.
Does the NCDC map created using real temperatures or NCDC ‘adjusted’ temperatures?
Oops! Is … not ‘Does …’
Looking at their time scale on the bottom just clarified something for me…
…they have 4 months to break hottest day records
What a waste of time. Now if they could consistantly figure out the winner of the first three races at Aqueduct on any given day, I might actually be impressed,
Do they have a similar map for the coldest day of the year?
JohnH: Count yourself lucky. It usually snows on my birthday, and my birthday is in September…..
Les, you must live in Montana!
As usual, Alaska and Hawaii seem no longer to be a part of the “United States” according to NOAA………..#-(
As usual, Alaska and Hawaii seem no longer to be a part of the “United States” according to NOAA………..#-(
But they aren’t connected, so 97% of pedants will say technically they are dis-united .
Yeah, but out here in California we can’t say, “Yes, but it’s a moist heat” like they do in the South.
Fall is summer here on the immediate West Coast (although Spring is up there too). Summer is as someone incorrectly quoted Mark Twain. We continue being entertained by tourists freezing in their shorts and t-shirts meanwhile we’re wearing our hoodies.
it’s a very interesting map: note how humidity delays the hottest day by two months in Texas compared with dry hot Arizona.
Why does this data set only go back to 1981? There were no thermometers in the US during the first 8 decades of the 20th century?
I thought with the new and improved NOAA maps only hyper reds were allowed and that everyday is a new record high for the US. “Doh!” – H.Simpson
A map of Hours of Bright Sunshine for July would give a most interesting comparison.
“The temperature increase after the solstice occurs because the rate of heat input from the sun during the day continues to be greater than the cooling at night for several weeks, until temperatures start to descend in late July and early August”
As Hans Errin indicates above I don’t know that I buy this as the reason for the delay. Sitting here in Central Texas it is seems tied to the drying of the ground through July which leads us to the higher August temperatures.
“tgasloli says:
June 27, 2014 at 3:02 pm
Why does this data set only go back to 1981? There were no thermometers in the US during the first 8 decades of the 20th century?”
Yep, my thoughts exactly….there are records in some places going even farther back.
I think they don’t want to show the 1930s, for instance, as they won’t be able to say
“it’s the hottest ever” (since we started, erm, measuring, er, cooking the books,etc., etc.).
Sixty year cycles probably have never occurred to them…then again, not much else does
either, unless it’s got funding attached to it…
With reference to ‘where is the page on “The Coldest Day o fthe Year”‘ which would be of interest to city managers with large homeless populations (to protect them from freezing to death) – send a note to the NOAA at: (from their web site)
For Climate Monitoring Products and Analyses – Email: cmb.contact@noaa.gov
I’ve been breathing for 51 years, been through droughts/floods/blizzards/lack of snow that freezes the ground to scary depths.
What were we talking about ?
Bill Illis (June 18, 2012 at 3:35 pm) wrote:
=
The seasonal lags for the ocean are about 82 days, freshwater lakes are about 49 days and land surfaces are 34 days.
[…]
It is big part of the picture; energy flows over time, that are not being addressed in the theory.
=
http://wattsupwiththat.com/2012/06/18/time-lags-in-the-climate-system/#comment-1012418
_
Bill Illis (December 7, 2008 at 6:25 am) wrote:
=
Land temperatures lag […] the soltices by about 30 days. The hottest/coldest part of the year is 30 days after the summer/winter solstice.
The oceans lag the equinox/solstice by about 80 days. The oceans are at their warmest 80 days after the solstice (hurricane season peaks on September 12th, polar ice melt peaks on September 12th, the actual sea surface temperatures peak on September 12th.)
=
http://wattsupwiththat.com/2008/11/25/adjusting-temperatures-for-the-enso-and-the-amo/#comment-61824
Jeff says:
June 27, 2014 at 4:13 pm
“tgasloli says:
June 27, 2014 at 3:02 pm
Why does this data set only go back to 1981?
Because “normal” in the context of weather is defined as a 30 year average with the final year ending in a zero. For example 2010. Shortly after 2020 rolls around the new-normals will be for 1991-2020. The idea is that most of us do not remember the 1930s so a perception of that warmth is not something of interest. But insofar as the weather seems to move in multi-decadal waves/cycles/oscillations (pick your term) then a recent 30 year period is more likely to catch the current year than if all the data is used – that just smears out things. Having established a purpose for the map, the creators thus chose a suitable metric.
–————
The long thin line on the west coast is interesting because that is where the bulk of the population of each state lives …
This fits S. CA well but not WA & OR. Not really important to the post – just an observation.
“John F. Hultquist says:
June 27, 2014 at 5:23 pm ”
The trouble is, 30 years (average or not) out of a longer cycle (60 years or so), are useless.
I don’t care if folks don’t remember back that far, picking parts of cycles makes it all to easy to
“lie with statistics” (truncated graphs, inconsistent indices, etc.).
To quote Carly, “perception is reality” when it comes to the CAGW agenda, so a good dose of the truth, including numbers going as far back as is reasonable, is the best place to start.
June 27, 2014
Jeff says:
June 27, 2014 at 5:54 pm
For this purpose you want data that is consistent with the current direction of the metric – be that up, down, or sidewise. Say temperature is now going sidewise (aka “the pause”). It seems that including the low temperatures of the 1970s (if such there were) would detract, rather than add, to the reasonableness of the analysis. The phrase “muddy the water” comes to mind.
Say you want to project the temperature at 5 PM. Would you plot Noon through 4 and make your guess or would you average the previous 24? Place your bet.
Vecchio, A.; Capparelli, V.; & Carbone, V. (2010). The complex dynamics of the seasonal component of USA’s surface temperature. Atmospheric Chemistry and Physics 10, 9657-9665.
http://www.atmos-chem-phys.net/10/9657/2010/acp-10-9657-2010.pdf