A cold, dry spell is keeping temperatures below normal and allowing urban valley pollution levels to rise once again in northern Utah.
The National Weather Service forecast called for daytime highs around 30 degrees Tuesday and the mid-30s on Wednesday under partly cloudy skies along the Wasatch Front. Overnight lows were pegged for the low- to mid-20s.
Although a long way from the weeks of "Red," or unhealthy air quality levels earlier this year, the Utah Division of Air Quality's breathability grades for Salt Lake, Davis, Weber and Utah counties were degraded on Tuesday to "Yellow," or compromised. Wednesday was expected to be no better.