It was the hottest day of the year in Washington on Sunday, the fourth 90-or-plus-degree day of 2012 and and the hottest day since last August.

After a cool start to June, the 92-degree high reading at Reagan National Airport seemed sufficiently elevated to satisfy longings for summer. Sunday’s temperature was 7 degrees above normal for the date. Yet the humidity was low enough to save the day from insufferableness.

This impression was supported by the heat index, a numerical gauge of discomfort. During several warm hours Sunday, the index was no higher than the actual temperature, and at times it even appeared to be a little lower.

Thus, at 2 p.m., with the temperature at 91, it was possible to say: Yes, but it feels like only 89.

Nevertheless, the 92-degree high was 1 degree above the year’s previous high temperatures, Saturday’s 91 and the 91-degree reading on May 29.

It also made Sunday the hottest day in 10 months. The last day with a higher temperature was Aug. 10, when the mercury reached 93.