Our Climate in Union County Oregon.
Union County is located in the northeastern Oregon.
Our climate in Union County The Grande Ronde Valley is surrounded by mountains and is a very flat valley with the Grande Ronde River flowing through it. The river meanders its way through the valley with many streams that connect to it. The largest creek is Catherine Creek that flows out of the West Wallowa Mountians. In Cove Mt Fanny has Mill creek that flows out of the South West Mountains. The Mount Emily range is located on the west side of the Valley with small creeks that feed the Grande Ronde River and Mount Harris and Mount Fanny are located on East side. To the North of Union County is the Indian Valley, Palmer Junction area and Cricket Flat and to the South is North Powder area were you can find rolling hills and a little dryer climate.
Union County´s elevation is about 2,700 on the valley floor.
While North Powder is about 1,000 feet higher in elevation. Air temperatures generally are about 7 to 10 degrees cooler in the winter and during the summer. The growing season is somewhat shorter also. The last frost generally occurs in mid to late May and can occur in mid to late September. The area has experience frost on a rare climate event in June and in early September.
Annual rain fall:
Union County rain fall is about 20 to 22 inches in the north county and in South County can be 12 to 15 inches per year.
Our climate conditions changes as we move into winter. In most cases the valley floor experiences an open winter, meaning snow fall duration is limited to several days to a week, although it does depend on the winters and each winter is different. The valley floor can experience drifting snow and occasionally the county roads and state highway. On the slopes of the Mount Emily the snow levels do increase and can stay for month or several months during the winter. This area also receives the most amount of accumulation of rain and snow. The area Mountains can have snow accumulations of up to 6 feet in the higher elevations.
The area has beautiful springs and you can general witness winter conditions changing beginning in late February to early March. Daffodils will begin blooming in the middle to late March and a very good sign of spring you will see the areas little league players beginning their spring training for their league games. April and May can see a general soft steady rain.
Our climate in Union County changes around mid July to warmer conditions. Residents will begin to notice a change from spring to summer in May sometime around the middle of May. I may not be uncommon to see the area temperature reach 80% decrees by late May. In June, it is not uncommon for Union County to receive up to 1 inch of rain. Starting in July the area can be witness to thunder storms that can cause wildfires and also release a large amount of rain all at once. These storms will come and go and can last through the middle of September. The county´s highest temperature will begin in the latter part of July and will continue through August, with the nighttime temperature cooling in the 50´s.
Residents will begin to notice air temperature changes in the middle of September, will much cooler nights. General comments from residents will be asking if you added the extra blanket on your bed, a good indication that the weather is changing. Frost will also begin around the middle of September and the leaves will begin changing first in the higher elevations. The first snow can occur in the mountains in mid to late October and the Grande Ronde Valley occasionally you can see snow in late November.