Quality of Life
Marion and Polk Counties lies along the western side of the northern part of the Cascade Mountain Range. Both counties are within Climate Division 2 (Willamette Valley) and Climate Division 4 (Northern Cascade) established by the National Climatic Data Center.
The climate of the Valley is relatively mild
throughout the year, characterized by cool, wet
winters and warm, dry summers.
The climate of the Valley is relatively mild throughout the year, characterized by cool, wet winters and warm, dry summers. The climatic conditions closely resemble the Mediterranean climates, which occur in California, although Oregon’s winters are somewhat wetter and cooler. Growing seasons in the Willamette Valley are long, and moisture is abundant during most of the year (although summer irrigation is common).
The Willamette Valley annual precipitation totals are between 35 and 45 inches. Most of this precipitation occurs during the winter. In the Valley, 70% of the annual total occurs during the five months of November through March while only 6% occurs during the three summer months. The seasonal difference in temperatures is much less marked than that of precipitation. There is a range of about 28 degrees between the temperature for January, the coldest month, and July, the warmest. Highs of 100 degrees or more seldom occur, and only in a few years since records began in 1892, have 0 degree or lower temperatures been observed. There is an average growing season of six and a half months.
The mild temperatures, long growing season, and plentiful supply of moisture are ideal for a wide variety of crops. In dollar value of agricultural returns, this is the most productive area in Oregon. Large orchards of sweet cherries are grown and processed here for maraschino cherries. Hops, filberts, walnuts, cane, and strawberries each contribute many millions of dollars to the annual farm income. A wide variety of vegetables are raised for both the fresh market
and to support a large number of processing plants located in the valley. This climate is also suitable for the production of a number of specialty crops including mint, several seed crops, and nursery stock, particularly roses and ornamental shrubs.
Average Temperatures and Precipitations
| Dec Jan Feb | Mar April May | June July Aug | Sept Oct Nov | Annual Average | |
| Salem, OR | |||||
| Avg. High | 48 °F | 61 °F | 79 °F | 64 °F | 62.8 °F |
| Avg. Low | 33 °F | 38 °F | 50 °F | 42 °F | 40.5 °F |
| Mean | 41 °F | 50 °F | 65 °F | 53 °F | 52.2 °F |
| Avg. Precip. | 5.7 in | 2.8 in | .90 in | 3.60 in | 39.3 in |
| Denver, CO | |||||
| Avg. High | 44 °F | 61 °F | 85 °F | 65 °F | 63.6 °F |
| Avg. Low | 17 °F | 34 °F | 55 °F | 36 °F | 35.7 °F |
| Mean | 31 °F | 48 °F | 71 °F | 51 °F | 50.1 °F |
| Avg. Precip. | .50 in | 1.8 in | 1.7 in | 1.0 in | 15.4 in |
| Eugene, OR | |||||
| Avg. High | 48 °F | 61 °F | 79 °F | 64 °F | 62.7 °F |
| Avg. Low | 36 °F | 41 °F | 51 °F | 44 °F | 42.8 °F |
| Mean | 42 °F | 51 °F | 66 °F | 54 °F | 53.3 °F |
| Avg. Precip. | 7.30 in | 3.6 in | 1.0 in | 4.5 in | 49.3 in |
| Las Vegas, NV | |||||
| Avg. High | 59 °F | 77 °F | 103 °F | 81 °F | 80.0 °F |
| Avg. Low | 35 °F | 51 °F | 73 °F | 54 °F | 53.1 °F |
| Mean | 48 °F | 65 °F | 88 °F | 68 °F | 67.1 °F |
| Avg. Precip. | .50 in | .30 in | .30 in | .30 in | 4.2 in |
| Portland, OR | |||||
| Avg. High | 47 °F | 61 °F | 78 °F | 63 °F | 62.2 °F |
| Avg. Low | 34 °F | 42 °F | 55 °F | 45 °F | 44.0 °F |
| Mean | 41 °F | 52 °F | 67 °F | 54 °F | 53.6 °F |
| Avg. Precip. | 5.1 in | 1.9 in | 1.0 in | 3.30 in | 36.5 in |
| Sacramento, CA | |||||
| Avg. High | 55 °F | 72 °F | 91 °F | 76 °F | 73.1 °F |
| Avg. Low | 38 °F | 46 °F | 57 °F | 49 °F | 47.6 °F |
| Mean | 47 °F | 59 °F | 74 °F | 63 °F | 60.8 °F |
| Avg. Precip. | 3.0 in | 1.4 in | .10 in | 1.4 in | 17.7 in |
| Seattle, WA | |||||
| Avg. High | 46 °F | 57 °F | 73 °F | 59 °F | 59.0 °F |
| Avg. Low | 36 °F | 42 °F | 54 °F | 45 °F | 44.0 °F |
| Mean | 42 °F | 50 °F | 64 °F | 53 °F | 52.1 °F |
| Avg. Precip. | 5.1 in | 2.5 in | 1.10 in | 3.60 in | 37.1 in |
Source: National Weather Data Source Center
