Last chance for a moonlight swim

Sundown in summer — and the city is transformed. Bird chatter gives way to cricket chirps. The wind slackens. Traffic and lawn mowers get tucked in. The suddenly gentle outdoors beckon, because the house is still stifling. It's cool out there.

Cooler still? The moonlight swim.

Pick a spot in the City of Lakes — or off any dock in the Land of 10,000 Lakes — on an evening in July or early August, and that 's the place and time for a moonlight swim. It's where you can plunge into the dark embrace of summer — the water feeling warmest on a cool night — and about the only time of year you could do such a fool thing in Minnesota without having to call for help.

Of course wading or diving into a Minnesota lake is a thrill on any summer day. But a moonlight swim is another species entirely. The very darkness adds intensity, enhancing sounds and the suspicion of what's in the water with you, and where. What did I just brush against? There's a sense of privacy.

No one can see me!

And if you forget the sunscreen, so what?

I'm beyond the tan line!

Also, it's probably wise to swim with someone or tell someone you're going for a nighttime swim. If you need help, there won't be as many people around as there are in the daytime. (And the few who are might think you're just some big old carp splashing around out there.) And even if you're good at celestial navigation, don't forget where you left your clothes.

This week, in the run-up to the supermoon, the moon will be high and bright in the few hours between sunset and beach-closing time. These are the nights when you can paddle out into Lake Harriet — the moonlight swim lake of choice for me and a few friends — with the moon riding just above the trees along the south shore and the downtown skyline providing a sparkling counterpoint to the north. Roll over on your back and you might see Vega overhead, beginning to assert itself against the darkening summer sky. These nights you might also catch the Perseid meteor shower. As you float out there, looking up, the idea of traveling through space becomes a little more real.

On a recent night, when we met at the beach, the new moon was just a low slice of smoked Gouda in the southwest, but the satin-smooth water was 80 degrees — swimming pool temperature. Even so, at 9 p.m., we were the only people on the sand, evidence that moonlight swimming can be an experience you can claim pretty much for yourself, even in the city. We waited a while for the sky to darken, then dashed in and headed for the buoys. We swam hard to generate some warmth, but it was delightful to feel the heat and frenzy of a summer workday wash away. The air temperature was 73, chilling us as we emerged. The mosquitoes had disappeared — along with the dozens of bats that had been chasing them. Around the lake, the shoreline trees molted into a black silhouette. Only a few path lights and moving headlights shone through. Walkers and bicyclists were fleeting shadows, their voices seemingly lowered by the night.

The moonlight swim is something we look forward to all summer. We were only in the water for a short time, wrapping ourselves in towels and fleece after maybe 20 minutes. But it was exhilarating, as well as ephemeral. A supermoonlight swim in the coming nights could very well be the last night swim of the year. The water will cool in the shortening days of August, and by September, well, goose bumps will be losing their appeal. In fact, next time out on the lake at night, it likely won't be the same at all. We could be skating.