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Why isn't the longest day the hottest?

Heat always takes its time

Earth doesn't just soak up the Sun: it gives some back

As long as it takes in more than it returns, it keeps warming up

Even after June twenty-first, that surplus lingers

The peak shows up three to six weeks later

The same lag plays out every day, around four in the afternoon

And the sea stretches the wait even further

Summer's heat is just the most patient of delays