I had a look and found a cloudless day on 02/25/2017, winter in the US so sun will have a low arch. The graph show no dips which would indicate that the wind vane or anemometer did nor cast a shadow over the sensors. Latitude / Longitude: N 30 ° 8 ' 45 '', W 95 ° 24 ' 46 ''. Maybe if you go further north or south from 30 °, it might be a bigger issue.
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