Parametric plots of smoothed climate variables at Manilla
“December 2016 hot with cold subsoil”

December raw anomaly data (orange)

In December 2016 both days and nights became hot, but the subsoil remained cold. Other variables were near normal. During the last six months all partially-smoothed anomaly values moved around the edges of the graphs.

 Fully smoothed data (red)

At the time of the latest fully-smoothed anomalies, in June 2016, most variables were moving rapidly towards cool and moist.
Daily minimum temperature and subsoil temperature, however, fell slightly from a peak in May. The subsoil temperature was normal, but the daily minimum temperature anomaly had reached a new record high for a smoothed value in May 2016: +1.34 degrees.

Subsoil temperature

The observed changes in subsoil temperature are a mystery. Generally, they are like those of daily maximum temperature, but with leads or lags as shown by curved arrows on the bottom right graph. They relate well to daily minimum temperature, as shown by the similar patterns on the bottom two graphs. This month, however, the raw anomaly of subsoil temperature is very low, while those of maximum and minimum air temperature are very high.

Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.
Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

 * Normal values for rainfall are based on averages for the 125 years beginning 1883.