I live in a rural area. I have an instrument shelter in my back yard, which houses my my AcuRite temperature instrument. The shelter is built of wood and ventilated. It is in the middle of my back yard, about 20-30 feet away from the house, and is not underneath any trees. The nearest NOAA station is in town, about 5 miles away.
Here's my dilemma. In the daytime, my highs are usually several degrees higher than those of the nearest NOAA stations. However, at night, this is not the case, and in fact my readings are usually lower, often by several degrees. I would expect that, since I live in a rural area. But what explains the high daytime readings? For instance, the highest temperature I recorded for August was 96. However, the highest reading of the NOAA station about 5 miles away for August was 91, I believe.
So, what would explain these discrepancies? Is it the instrument, or something else? Thanks for any info.
Here's my dilemma. In the daytime, my highs are usually several degrees higher than those of the nearest NOAA stations. However, at night, this is not the case, and in fact my readings are usually lower, often by several degrees. I would expect that, since I live in a rural area. But what explains the high daytime readings? For instance, the highest temperature I recorded for August was 96. However, the highest reading of the NOAA station about 5 miles away for August was 91, I believe.
So, what would explain these discrepancies? Is it the instrument, or something else? Thanks for any info.
Have you tried a regular thermometer for comparison? Is your shelter painted white? How is it ventilated? How is the Acurite rated for accuracy? It should be listed on their site +/- X amout degrees. NWS ASOS readings are considered within specs if temperatures are within 4 degrees with test equipment. Generally though they are calibrated within 1 degree. Also, the surrounding vegetation of the ASOS will affect temperature. When I worked at NWS before retirement this spring, it was not unusual that the temperature in the instrument shelter at the office to be 3 to 5 degrees warmer than the ASOS 1 mile away during the summer months. The ASOS was located near an alfalfa field which was green and kept daytime highs cooler. So many variables, that the only way to know for sure is to compare your readings with another accurate thermometer on site, side by side.