Heat wave. As I write on April 19, it’s 84 degrees at our place near Milanville, the first 80-degree day since September 14, 2003. Following a weekend in the high seventies, there’s been a flurry of activity in the plant and animal worlds.

Shad. River temperatures at Callicoon and Barryville have risen to mid-fifties from highs of 47 degrees a week ago. A recent report of the Delaware River Shad Fishermen’s Association notes “loosely packed schools” at the Route 202 Bridge, 16 miles above Trenton, with “catches reported up to the Delaware Water Gap.”

Elm flowers. Early wind-pollinated flowers, such as those of the American elm, are already setting seed. Elm flowers generally occur in clusters near the tips of twigs, but for scale, I placed the single flower in my photograph on a penny. Tiny black sacs in the picture once held pollen; an arrow points to a developing elm seed or “samara.”

Our first encounters with wind-pollinated tree flowers are often after they whither and litter town city streets and sidewalks. That such fragments can create the acorns and winged seeds of maples and elms seems remarkable, but no more so than the precise timing that unfolds each flower before the earliest leaves.