In May, 1952, the station was moved to its present location at OSU's Hyslop Experiment Station, six miles northeast of downtown Corvallis. The station is just off U.S. Highway 20 at latitude 44.63 degrees N, 123.20 degrees W, and at an elevation of 225 feet above sea level. Since 1952, observations have been taken at 8 a.m. by personnel from the OSU Crop Science Department. All data recorded is assigned to the date the observation is made. This means, for example, that recorded high temperatures almost always occur on the previous calendar day. This convention, however, has been adopted as policy for all cooperative observatons archived at the National Climatic Data Center.

In 1983, all historical data was entered into digital format on a computer system. Daily digital values are now available for over 100 years of record.

Climatologists generally define "normal" as a 30-year arithmetic average for a given parameter. Every decade, new normal values are computed using the most recent 30-year period. The values in this publication represent an update of the 1961-1990 normals that have been in use for the last 10 years. Tables listing individual monthly values are confined to the 1971-2000 period as well. Readers who require longer data sets may contact the Oregon Climate Service for more information.

Corvallis Climate
Corvallis is located at the western edge of the Willamette Valley, a north-south oriented valley which lies between the Coast Range and the Cascade Mountains. The valley extends from Eugene in the south to Portland in the north, a distance of about 110 miles. The valley is near enough to the Pacific Ocean (about 40 miles ) to be influenced considerably by marine air, yet far enough away that immediate marine effects (such as coastal fog and drenching rains) are abated somewhat. Valley locations receive 40-80 inches of precipitation per year, depending upon elevation. In general, an increase in elevation correlates with an increase in precipitation.

Corvallis temperature and precipitation values follow a pronounced annual cycle that closely resembles most other coastal stations in the western United States. The vast majority of Corvallis annual precipitation fall during the cool season (November - March), while summers are generally warm and dry. Extreme temperatures are uncommon.

Corvallis has an average of about 220 frost-free days per year. The average date of the last 32°F temperature in the spring is April 20, while the average autumn date for the first frost is October 27.