A digital device reads off the temperatures, wind speed, and barometer and anemometer readings from amateur radio operator Eddie Miseiwicz home weather station on Wednesday, Jan. 22, 2025 at his home near Belle Vernon.
Steve Fazekas' citizen weather observer station in Winfield recorded a temperature of 15 degrees below zero just after 5 a.m. Wednesday.
Fazekas' reading came in just below the Pittsburgh region's lowest temperature on record for Wednesday's date -- minus-4 degrees Jan. 22, 1936 -- but it won't go in the record books. Temperatures measured at Pittsburgh International Airport are considered official by the National Weather Service and, on Wednesday, the low there came in at minus 9 degrees.
For Fazekas and thousands of other trained weather volunteers across the country, recording the temperature is a daily routine, and they report their findings and observations to the National Weather Service around-the-clock seven days a week.
"That helps the weather service take a look at the particular (advisories or alerts) they have out, and it enables them to upgrade it or downgrade it," Fazekas said.
"We've been doing it religiously every day."
The NWS Cooperative Observer Program, also known as COOP, plays a crucial role to fill the gaps in the nation's weather observation network, especially when it comes to reporting extreme cold, said John Darnley, observation program leader for the National Weather Service Pittsburgh.
In Fazekas' case, his station connects to his cellphone, and he is able to make his report to the weather service from there.
"By having a network of human observers, the COOP program adds a layer of reliability and detail to weather data that purely automated systems might not capture, especially in extreme conditions or after equipment malfunctions," Darnley said.
And temperature reporting in the 35-county National Weather Service Pittsburgh region has an added layer of complexity.
Variances in temperature based on locations are common because of the area's terrain, said Shannon Hefferan, weather service meteorologist.
"You have pockets of temperatures that will vary across the region," she said.
Hefferan said the National Weather Service sees the temperature variances most in ridges in Tucker County, W.Va., where there can be anywhere between a 5- to 10-degree difference from the top of a ridge to the bottom of a valley.
"Cold air sinks because it's more dense, and warm air rises," Hefferan said. "In certain environmental conditions, the ridge top can be warmer than the valley."
Other factors that play into temperature differences include rivers, the dew point, wind, sensitivity of sensors and snow pack, Hefferan said. Even a drive from the Sewickley Bridge to the National Weather Service office in Moon Township can see a 5-degree swing in temperature.
Often, it can be warmer along the rivers -- but not when they freeze over, she said.
COOP involves thousands of volunteers nationwide who collect daily weather data, including precipitation, temperature and sometimes other meteorological variables, such as snowfall or evaporation, Darnley said.
Another local volunteer is Eddie Misiewicz, whose sensor at his Belle Vernon home recorded a low temperature of minus 8 degrees Wednesday morning.
Misiewicz has been a certified weather observer for more than 50 years. He can report information like temperatures, windchill factors and more through calling weather service or through NWS Chat, a real-time instant messaging program.
But, he said, this is the coldest winter he can remember for decades. National Weather Service officials said Wednesday morning it hasn't been this cold in the Pittsburgh area since February 2015.
"The past several winters have been mild," Fazekas said. "It's been several years (since it's been this cold.) Minus 15 at air temperature -- it's brisk."
How they do it
Most spotters use standard, weather station temperature sensors that can be integrated with their reporting system.
"There's so many out there," Misiewicz said. "Some are capable of being on the internet."
To accurately record weather, the sensors must be away from a house or concrete, Misiewicz said. His sensor is 33 feet above the ground, about a foot tall, and 6 to 8 inches in diameter.
"They need to be out far enough to measure air temperature," he said.
After collection, data is quality-controlled by weather service staff before being placed into national databases, Darnley said.
Data can contribute to weather warnings, frost and freeze alerts or public health advisories during cold snaps, he said.
Extreme cold events are documented in daily and monthly reports and can become part of long-term records used for analyzing trends in cold-weather patterns.
A moderate warmup is on its way, according to meteorologists. A change in air mass Thursday is projected to bring daytime highs back into the 20s in the region; but many places won't crack freezing until this weekend.
Regardless, trained weather observers will continue to have their boots on the ground.
"This is something we repeat every day -- snow, rain, sunshine," Fazekas said.
"It's something that gets to be part of your daily routine. ... It helps to provide ground truths to the weather service, which is valuable."