This graph is a log of indoor and outdoor 7-day mean temperatures at my low-energy solar-passive house at Manilla, NSW. Indoor mean temperatures are in red, and outdoor mean temperatures in black. Both logs show the same cycles of temperature with a period of two to three weeks. Indoor cycles have a much smaller amplitude.
Raw anomaly data for June 2011 (shown in orange) are a little strange.
Daily max temperature, shown on the x-axis of all six graphs, has stalled without quite rising to normal from the extreme cold of last October.
Two variables indicate severe drought: Rainfall was very low, and so was the early morning Dew Point.
Most other variables are near normal, or slightly to the “flooding rains” side of normal.
Percent of cloudy mornings (>4 Octas) remains stable at a very high positive anomaly. For a calendar month that had 35% cloudy mornings in the reference decade beginning in 1999, it now has 55% cloudy mornings.
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.
June began and ended with warm sunny days. The second week was cold: the 9th had a maximum of only 12° after a frosty night of -2.7°. Days from the 12th to the 15th were not much warmer, made miserable by overcast and rain, but the nights were warm. The 8/8 cloud recorded on the morning of the 24th was fog, which cleared to a blue sky at 10:45.
The highest rainfall reading was only 8 mm, recorded on the 22nd. Five rain days totalled 17.8 mm.
Of the mean temperature readings, only the mean daily maximum was a bit lower than usual. Days were not as cold as in June 2007. This time, there were 14 frosts, which is near the decade average.
The rainfall of 17.8 mm is rather low: on the 20th percentile for June. (The long-term June average is 44.3 mm.) June rainfalls have fallen rather steadily since June 2005, the sixth wettest on record at 109 mm. Nearly all rainfall totals for groups of months (up to 360 months) continue to be near normal. Only those for three months and four months are below the 25th percentile.
Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.
Fully smoothed data points for spring (SON) of 2010 are plotted in red on the left edge of the graphs. They show that several variables reached peak values during the season. First, temperature range anomaly reached a minimum in September. Next, in October, daily maximum temperature anomaly reached a minimum, rainfall anomaly a maximum, and Dew Point anomaly a maximum. In November, subsoil temperature anomaly reached a minimum. Cloudiness anomaly may have reached a maximum in that month, but perhaps smoothed December or January values will be higher. Daily minimum temperature anomaly did not peak. Through spring it fell steadily from a high positive value.
In a “weatherzone” post, I noted a tendency for variables to peak in a particular order.
“For a “flooding-rains” peak:
Not much is different in this case. In particular, daily temperature range was the first to peak (WHY?), and subsoil among the last. However, the time of rainfall maximum did not precede the time when daily maximum temperature reached a minimum.
During summer (DJF) most variables seemed to be moving towards “droughts” but this pattern broke down in autumn:
I am surprised that extreme cloudiness and extreme low humidity occur together. I am also puzzled about the weak association between daily maximum and minimum temperatures. This is a worry because daily minimum temperatures provide the most consistent signal of climate change during the last century.
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.
May had five rain days (usually only three) but they came very late. The highest rainfall reading, 19.6 mm on the 23rd, ended a 35-day dry spell. Before the rain, the air had become extremely dry. The morning Dew Point on the 17th was -9.3° and the daily minimum temperature on the 15th -2.8°: both were 13-year record low values for May. The daily temperature range reached 24.9° on the 18th.
With the rain came cloudy, cold days. The 30th, with a maximum of only 11.1°, was the coldest May day in this record. It was nearly two degrees below the previous coldest: 12.9° on 29/5/00.
Mean temperatures were a little below average. There were 11 frosts, compared with the usual six.
After sunny April, May was back to the extreme cloudiness of the last three years. The air was not humid at all, however. The mean Dew Point was only slightly higher than in the droughty May of 2006.
The rainfall of 43.2 mm is on the 64th percentile for May, and just above the long-term May average (39.3 mm). May rainfalls have been low (or very low) for a number of years: this was the wettest May since 1998 (74 mm). Rainfall totals for groups of months (up to 360 months) continue to be near normal.
Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.
climate by surly 