The National Weather Service has issued a heat advisory for most of Western Washington this weekend. The advisory covers Saturday afternoon through Monday evening, when temperatures in the mid-80s to low 90s are forecast. Temperatures could reach 15 to 20 degrees above Seattle-area average for May.

King County is prepared to roll out its new extreme heat mitigation plan, which Crosscut wrote about last summer, as temperatures rise this spring and summer. Writer Hannah Weinberger shared lots of community resources in this story.

After the past few hot summers, Seattle has evolved to no longer be the U.S.’s least air-conditioned city. You may be eligible for government help to acquire an air conditioner. More than a thousand Washington residents have benefited from this program.

And here’s a very practical story on how to keep cool even without air conditioning, including a very specific plan for when to open and close your windows.

The National Weather Service, public health officials and Crosscut’s Hannah Weinberger want people to know that even in Washington’s coolest regions, heat can be deadly. 

King County’s Trailhead Direct service returns for its fifth year this weekend to shuttle car-free hikers between Seattle and North Bend trailheads on weekends and holidays through Sept. 4. 

The county invested in a shuttle service in 2017 amid concerns about both climate change and recreation access. It opened some of the region’s most popular hiking trails to those who either don’t use cars or who don’t want to deal with the traffic congestion that plagues these trails during peak hours. Cyclists, rejoice: Each shuttle includes bike racks with space for two to three bikes. 

The route starts at the Capitol Hill light-rail station every half hour, but users can also board at the Downtown light-rail station and the Eastgate freeway station. Stops include the North Bend Park & Ride and the trailheads for Little Si, Mt. Si and Mt. Tenerife. The longest ride takes one hour between Capitol Hill and Mt. Tenerife. 

Users can walk or roll onto shuttles and pay as they would for bus and light-rail rides. The one-way $2.75 fee can be paid using cash, an ORCA card or the Transit GO app. Users 18 and under ride for free.

Eastern Washington cities are historically hotter and drier than their Western peers, but this year, some Eastern cities have been getting hotter sooner. 

On Sunday, Spokane tied its hottest April 30 on record: 82 degrees Fahrenheit at Spokane International Airport, tied with that date in 1981. (Records have been kept in the Spokane area since 1881.)

The Spokane forecast surprised local forecasters like Jeremy Wolf of the National Weather Service in Spokane. It’s uncommon to see such high temperatures in Spokane after such a cool spring, Wolf says. 

Spokane had seen its first day at or above 70 degrees only a few days earlier, April 26, when temperatures reached 71. The Inland Northwest experienced a colder-than-normal April, with temperatures 2 to 6 degrees cooler than average. The weather this past weekend was 15-20 degrees hotter than average.

“The temperatures themselves weren’t abnormally hot by summer standards, where we often are in the 90s every day, or for several days. But yes, this was still pretty warm for early in the season,” Wolf says. 

The National Weather Service temperature outlook for May, June and July suggests hotter-than-average temperatures across the state, including Western Washington. The Service is also expecting temperatures in the 70s in the Seattle area on Tuesday and Wednesday. The average spring temperature for early May in Seattle is 63 to 64 degrees. 

The National Weather Service issued some safety warnings for recreationists who spend time near water or melting snow. Water rushing into rivers causes them to run faster and higher; hiking or skiing in melting snow comes with a greater avalanche risk; and lakes and streams are still cool enough to cause hypothermia. Wolf says rivers have been steadily rising since the warm temperatures began, and forecasters are watching for floods this week in nearby Idaho.

As spring weather rolls into town, weekend conditions will be perfect for outdoor activities, including one of the biggest citizen science scavenger hunts of the year. 

From April 28 through May 1, Washingtonians and people in at least 445 cities around the world are being asked to help assess how local wildlife are doing by participating in the eighth annual City Nature Challenge. 

People are invited to use their cell phones and the free species identification app iNaturalist to document and identify as many individual plants and animals as they can this weekend. The event is sponsored locally by the Woodland Park Zoo, the Point Defiance Zoo & Aquarium, and the Northwest Trek Wildlife Park.

The data isn’t only fun to collect, but also possibly valuable to scientists and their conservation work.

“By engaging the public in making nature observations in this global event, we help to generate more local biodiversity data than you would normally get on a regular weekend; people also learn about iNaturalist and then can use it more regularly to contribute biodiversity observations into the platform and different projects,” says Katie Remine, Woodland Park Zoo’s living northwest conservation manager.

The Challenge started in 2016 as a friendly competition between two California science museums’ community science teams hoping to improve patrons’ awareness of local biodiversity. Seattle organizations joined in 2017, and the zoo’s Brianna Widner says metro-area participation has increased annually since then, with 7,705 observations of 1,280 different species from 654 participants last year. 
Historically, Washington has been one of the more diverse U.S. states; a 2002 NatureServe study found it was home to 3,375 species at the time, making it the 20th most diverse state with the 13th greatest number of endemic species.