• COUNTRYWIDE (adjective)
The adjective COUNTRYWIDE has 1 sense:

1. occurring or extending throughout a country or nation

Familiarity information: COUNTRYWIDE used as an adjective is very rare.

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Sense 1 countrywide

Meaning:

Occurring or extending throughout a country or nation

Synonyms:

countrywide; nationwide

Context examples:

the event aroused nationwide interest / a countrywide fund-raising campaign

Similar:

comprehensive (including all or everything)
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Контекст.
Most of Thailand has a Tropical wet and dry or savanna climate (Aw) according to the Köppen climate classification, while the South and the eastern tip of the East have a tropical monsoon climate (Am); countrywide, temperatures normally range from an average annual high of 38 °C (100 oF) to a low of 19 °C (66 oF).
[...]
Central Thailand, the north, northeast and east have three seasons: hot (February / March to June), rainy (June to September / October) and cool (October to January / February). Countrywide, humidity is high almost all year.
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Как вариант - "в целом по стране"?
Другие варианты приветствуются.

p.s. МТ на 'countrywide' дает "по стране" - тоже, в общем-то, неплохо.

мне это слово не показалось редким или малознакомым

и если судить по пассажу

Sense 1 countrywide

Meaning:
Occurring or extending throughout a country or nation

Synonyms:
countrywide; nationwide

... когда в качестве синонима слова countrywide предлагается ... um... countrywide, статья странноватая