Creation of a semicontinental climate: an apparent solution to the NE of US and the long subtropical strip (hot, average)

[Kauan Mateus Kubaski]

The semicontinental climates could be defined (Dt). The high average would be from 28 ° C to 32 ° C and a low average of -2 to -6 ° C. This would include climates from southern Boston to Richmond that are different from southern climates, Cfa (Houston, Atlanta, Jacksonville, Dallas and New Orleans) with those from the interior of North America and in greater latitudes: Chicago, Detroit, Minneapolis, Milwaukee and Kansas City (Dfa).

Failing any of these criteria the isotherm would anyway be 0 ° C for Boston to fall reliably on Dfb/Dfa and Norfolk on Cfa - city without doubt subtropical in terms of vegetation. As I would go to the interior with border to Dfa, but as said not meeting this specific criterion transits right from Cfa to Dfa. Which also corrects and better models the scheme of Trewartha which includes as oceanic Midwestern cities.

Boston has the temperature between <-2 and> -6 but the temperature is> 28 ° C (cool for a semicontinental), the remainder follows the 0 ° C isotherm and the Köppen system, hence Dfa.

[Kauan Mateus Kubaski]

I found Köppen's definition of the subtropical climate and the climatologist understands it as temperate, which explains the long area Cfa:

"In the subtropical belts, the temperatures are moderate during at least one and not more than eight months, while the high position of the Sun is predominant during a hot period of at least four months. In these belts, even more extreme heat is reached than near the equator due to longer days and less cloudiness. In many regions on the map, this belt is divided into two or three sections by a red and a blue line: First, an almost tropical belt can be distinguished, where the moderate, relatively cool season, with daily temperature means below 20◦ C, is short and lasts less than four months. In the rest of the belt, the hot season lasts less than eight months.
On the southern hemisphere and on the oceans in general, this rest of the subtropical belt shows no really cool months with mean temperatures below 10 ◦C (with the exception of small bands on the eastern coasts of the continents). However, on the continents of the northern hemisphere, the subtropical belt includes extended regions, where the temperature of the coldest months is below
the value mentioned and therefore, one can call it a proper winter. Inner China and the Southern states of the North-American Union belong, with the exception of the southern coast, to this part of the subtropical zone. Likewise, the southern section of the aralo-caspian basin, the central parts of Persia, Syria and Arabia as well as parts of Greece and southern Italy form part of it.
To identify the red line on the oceans and in the mountains in the lower latitudes would have required more material and furthermore, would have been worthless in those cases, where the total annual variation is very small. Because if the temperature deviates by 1 or 2 °C from 20 ◦C at the most, it hardly matters whether this happens for less or more than four months. Only where the annual temperature variation is large, such as in the SaharaE1, both sections of the belt become broad and their distinction becomes important. The temperate belts of both hemispher".

Source: http://koeppen-geiger.vu-wien.ac.at/...pen_1884_2.pdf