Photo/IllutrationThe water level rises in the Tenchigawa river in Saka, Hiroshima Prefecture, on June 7, leading an evacuation advisory being issued for the area. (Kohei Higashitani)

The Japanese Society of Hypertension in April revised its guidelines on acceptable blood pressure from "under 140 systolic/90 diastolic" to "under 130/80."

That was bad news for me. My numbers, which narrowly fell into the pre-revision acceptable range, no longer do.

I now have to pay more attention to my lifestyle and diet, like going easy on ramen.

Blood pressure numbers are pretty clear-cut, but there are numerical standards in society that are not.

One example is Japan's alert system for natural disasters.

It is hard to tell, just from reading what it says, which is more dangerous: "Flood Alert" or "Special Heavy Rain Alert."

This problem was pointed out last year, after torrential rains triggered lethal floods in western Japan.

To remedy this, the Japan Meteorological Agency introduced a new five-level alert system last month prior to the annual "tsuyu" rainy season.

The system is based on past data kept by the agency and local governments.

The highest alert level, 5, represents a situation where a disaster has already occurred and everybody must fend for themselves for survival.

But level 4 for "full evacuation" is the one that needs to be watched most carefully. And this serious alert went into effect on June 7 in Hiroshima and Ehime prefectures.

An evacuee, shown on TV screen, said, "I haven't forgotten the disaster of last year, so ... ."

Everyone ought to be mentally planning what to do if and when they find themselves in a similar predicament.

The Japanese expression "tsuyu-gomori," which translates as "staying home during tsuyu," conjures serene images of the traditional Japanese tsuyu with people reading a book quietly and listening to the gentle patter of rain.

But those days are gone. In recent years, I have come to automatically associate "ferocity" with the very word tsuyu, which is written in kanji for "ume" (Japanese apricot) and "rain."

Blood pressure fluctuates according to one's state of health or level of physical exertion. Just as people can be subject to mood swings when they look at their blood pressure numbers, the weather's menace fluctuates, too.

The season that keeps us on our toes is now back.

--The Asahi Shimbun, June 8

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Vox Populi, Vox Dei is a popular daily column that takes up a wide range of topics, including culture, arts and social trends and developments. Written by veteran Asahi Shimbun writers, the column provides useful perspectives on and insights into contemporary Japan and its culture.