The National Oceanic and Atmospheric Administration announced its once-per-decade update to climate averages Monday.
The new data moves the 30-year average range from 1991 to 2020. It offers a baseline reference to compare yesterday’s weather with tomorrow’s forecast, NOAA writes on its website.
“Most people will notice it in the sense that when we talk about temperatures 10 or 15 degrees above normal or below normal,” said National Weather Service Boise office forecaster Josh Smith. “There are some changes usually over those period of years.”
Maps show average temperatures in most of Idaho rose by one-half to three-quarters of one degree Fahrenheit. Populated areas of the Snake River Plain had a full degree increase in average temperature.
Measured precipitation declined across the region, but average precipitation in The Wood River Basin and several areas in eastern Oregon declined about 10%.
“It's a pretty significant change for us,” Smith said. “It just tells us that the trend is less precipitation for the West and warmer temperatures. That was the trend for the last 30 years and it doesn't look like that's going to change.”
Regionally, the populated area around the Great Salt Lake also rose by a full degree. In northeast Montana and parts of the Dakotas, average temperatures actually fell slightly.
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