Minnesota naturalist warms to the idea of summer's arrival

Rejoice: Astronomical summer begins at 4:44 p.m. Saturday in the Northern Hemisphere. That's when Earth's orbit is positioned so that the north polar end of its axis leans at the full 23.5-degree angle toward the sun, giving all parts of Earth north of the Arctic Circle constant daylight, and the whole Northern Hemisphere the year's longest span of daylight. Some other notable things at the summer solstice:

• In the metro, we have 15 hours and 37 minutes of sunlight (began Thursday, through Tuesday). We lose one minute Wednesday. In the southeast, Winona has 15 hours and 30 minutes of sunlight, and Hallock, Minn., in the extreme northwestern part of the state, has 16 hours and 15 minutes of sunlight.

• Though the sun is highest in the sky now (68.5 degrees above the Twin Cities at noon) it will take about five weeks until we experience our warmest days. July 26 is statistically our warmest day of the year because of the lag time it takes to heat the earth's surface to the maximum. Radiation given off by the earth heats the atmosphere.

• Birds begin singing close to 4:20 a.m.; American robins first. A trained listener can pick out two dozen different bird species in the morning chorus. Young house wrens, song sparrows, blue jays, and northern cardinals are among those fledging.

• Female eastern cottonwood trees continue to "spit" much cotton. Gardeners are picking strawberries, the mouthwatering fruit high in vitamin C. Garden and wild roses are at or close to bloom peak. June is rose month.

• Baby raccoons, skunks, deer, chipmunks, gophers, and other wildlife sometimes are out wandering around. These are not orphaned young. Their parents are probably hiding — they are more cautious.

• If you missed the crab apple, apple and lilac bloom in the Twin Cities area a month ago, or just want to experience it again, take a drive along the North Shore to Silver Bay, Lutsen or beyond.

Jim Gilbert observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.