Right on cue, the much hyped “pneumonia front” hit Chicago shortly after 5:30 p.m. Tuesday, sending the official temperature at O’Hare International Airport plummeting from 81 degrees to 66 degrees in short order.

The giant snapping turtle spotted in the Chicago River became a viral sensation this week. But the river is home to lots of wildlife, thanks to ongoing efforts to clean up the waterway.

The Social Security Administration released the annual list Friday. The agency tracks baby names in each state based on applications for Social Security cards, with names dating to 1880.

Millions of birds will pass over the Chicago region this weekend as migration kicks into high gear. Want to be a good host? Turn off your lights.

The two unidentified plovers — one male, one female — that had joined Imani at Montrose have flown the coop, temporarily dashing the hopes of plover monitors for a love match and successful nesting season in Chicago.

Every time you flush, the waste disappears in a swirly whirl, never to be seen again. It’s magic! Actually, it’s science and engineering. WTTW News Explains. 

Lincoln Park Zoo said farewell today to a 300-year-old bur oak, but the tree will live on in multiple ways.

The peak water levels this spring will likely rank in the top 10 of all time in many places, but the National Weather Service said river levels will generally remain well below past records. 

A mystery vandal is once again undoing ecological restoration work at LaBagh Woods.

It's time for the annual City Nature Challenge, a friendly global competition among hundreds of cities, running from Friday through Monday. Here's how to submit nature observations and boost Chicago in the standings.

There’s a love triangle brewing at Montrose Beach, where Imani the piping plover has been joined by a mystery bachelor and … a female.

Chicago’s birders are celebrating the arrival of Imani at Montrose Beach. The piping plover is a 2021 chick of Monty and Rose.

A small number of people had to leave their homes in Wisconsin as the river kept rising. Others stacked sandbags in the small community of Buffalo, Iowa, in anticipation of flooding this weekend and early next week.

More than 20 years after residents began their fight to save the stair-step limestone wall at Promontory Point on the south lakefront, the Point was declared an official Chicago Landmark during Wednesday’s City Council meeting.

Crews are scheduled to begin removal of the ancient bur oak on May 1. The zoo is planning Arbor Day events on April 28 to give the tree a celebratory farewell.

Known as one of the oldest-recorded meteor showers, the Lyrids are expected to produce 10 to 15 meteors per hour for three nights centered around its peak of 8:06 p.m. CST on Saturday, according to EarthSky.