A question this station cannot answer about itself. A climate normal is a thirty-year mean and this mast has been up for rather less, so the long record on this page is not this station's.
That the gap between the two baselines is a trend. Two periods and the difference between them is a difference, and a gradient through two points is not a measurement. The chart at the top does fit a line, and that is a different claim about different evidence: twenty annual means are twenty measurements and support a slope with an error bar, which is published beside it. Where that error bar spans zero the line is not drawn at all.
That a difference between the two baselines is necessarily climate. The published averages end in 2000 and the monthly series begins in 2004, so there is no stretch of time where both describe the same weather and can be checked against one another. Where every recent year sits clear of the older figure — never once reaching it in twenty years — the honest reading is a change in the record rather than in the weather, and that column is withheld with the count printed.
That a month with holes in it was ordinary. A month this station missed a fortnight of has a mean that is not a mean of that month. Those get no anomaly at all rather than a quiet one, and the days observed are printed in place of it.
That the two means are interchangeable. Every published normal in the world is the average of daily (max + min) / 2, because two readings a day from a thermometer in a screen was all anybody had. This station takes a reading a minute and can compute the true 24-hour mean, which sits below the older definition wherever days warm faster than they cool. Comparing the one against the other would manufacture a cold anomaly every month, of about the right size to look like weather. The comparison here is midpoint against midpoint, and the anchor's own definition is measured rather than assumed.