If you thought the last few days have been colder than normal — you weren’t wrong.
The official daily low temperature of Tooele County dropped a few degrees after Saturday, Jan. 28, reaching single digits for a couple days.
The low temperature at the National Weather Service’s Tooele Valley weather station in Erda on Jan. 28 was 35 degrees, by Monday, Jan. 30 the low dropped to 9 degrees. It rose 10 degrees on the following day.
February started with warmer lows of 17 and 19 degrees on Feb. 1 and 2.
The 30-year average low temperature for January in Tooele County is 22 degrees, according to the National Weather Service.
As low as it was, Tooele has been colder, the lowest recorded temperature in Tooele was -16 degrees reported on Dec. 3, 1990, according to the National Weather Service.
While the official low on Jan. 30 was 9 degrees, the Transcript Bulletin received reports from readers around the county of temperatures from 3 degrees to -1 degree.
With the cold air, Tooele County’s air quality also dropped.
On Feb. 1, the 24-hour average concentration of PM2.5 rose to 12.3 µg/m³ [micrograms per cubic meter], putting the County’s air quality at the yellow, or moderate, level, one level below green, or good.
PM2.5 refers to microscopic particles, or particulate matter, that have a diameter of less than 2.5 micrometers, about 40 times smaller than the diameter of a strand of hair. The particles can reach deep into the lungs aggravating asthma, allergies and other respiratory and heart conditions. Long term exposure to PM2.5 has been associated with lung and heart disease.
The upper threshold for the green level of PM2.5 is 12.1 µg/m³, which takes the air quality into the yellow level.
For most people air quality at the yellow level is still acceptable but for people that are unusually sensitive, yellow air quality means they should reduce prolonged or heavy outdoor exertion. They should watch for symptoms such as coughing or shortness of breath as signs to take things easier, according to Department of Air Quality guidelines.
Tooele County’s air quality was rated at yellow for Feb. 1 and 2, with the PM2.5 level reaching 13.9 µg/m³ at 10 a.m. on Feb 2.
The PM2.5 upper level for yellow air quality is 35.4 µg/m³.
The Utah Department of Air Quality’s three-day forecast predicts that Tooele County’s air quality will stay at the yellow level from Feb. 2-4.
During yellow air quality days in Tooele County solid fuel burning devices must not be used and open burning may not occur; including fire pits, fire rings, and campfires. People are encouraged to reduce vehicle use by consolidating trips, according to the Department of Air Quality.
Between the cold air and hazy air, if you’re still watching the snow pack for Tooele Valley, the snow water equivalent as of Wednesday morning, Feb. 2, in the mountains above the Tooele Valley- Vernon Creek Basin was at 198% of the median value for Feb. 2, and at 118% of the SWE for the medium peak day of April 5.