Sunday, October 2, 2016

September 2016 Summary

A very hot September and back to the dry 

Just like August, September was 3.3 degrees above average and just like the previous month it was also the 5th hottest in the 100 years of records in the region.  But whereas last time we had to go back to 1959 to find a hotter month this time we only have to go back to last year when September was over 4 degrees above average.

This year there were a couple of days over 30 early in the month and there was another warm streak in the middle.  For the last week the temperature really dropped and although it might have seemed a lot colder it actually just went down to the average.

We might have to soon start using the D word again as this month only saw 28.2 mm of precipitation, this is less than a third of the average of 87.8 mm.  The annual precipitation total has been jumping around the average all year and with this dry month we have gone under again (669.0 mm this year – 685.2 mm average).

Summary for September 2016:
Maximum Temperature 32.8°C
Minimum Temperature 3.3°C
Average Daily High Temperature 24.2°C (Long term average 20.4°C)
Average Daily Low Temperature 11.4°C (Long term average 8.6°C)
Total Precipitation 28.2 mm (Long term average 87.8 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)

Sunday, September 4, 2016

August 2016 Summary

The hottest August in 55 years and the wettest in 30 

The month of August was the hottest we have seen since 1959 and the 5th hottest in the 100 years of records in the region.  There was only 1 day that was colder than average and that was only by a less than a degree.  The overall temperature was over 3 degrees above average, the most above average month this year.

Drought? What drought? After 3 really dry months in a row, this August was the wettest once since 1985 with 155.6 mm of precipitation.  This was almost as much as we had in the previous 3 months combined (167.6 mm).  It also puts it at the 7th wettest August in the region.

Generally we don’t see weather that is overall warm and wet at the same time, looking at a graph of temperature versus precipitation anomaly (see below), you can see that 2016 is out on its own towards the upper right of the graph.  Note that the crazy total for 1915 was caused by a recorded daily precipitation of 175.3 mm on the 4th which is more than 100 mm more than any other station recorded that day in the area.  So I see that data point as suspect, but even if you take 100 mm of the total is was still by far the wettest August we have seen in the region.

Given the wet month it is not surprising that the total for the year of 640.8 mm has gone above the average of 596.0 mm for the end of August.

Summary for August 2016:
Maximum Temperature 33.6°C
Minimum Temperature 10.5°C
Average Daily High Temperature 28.4°C (Long term average 24.8°C)
Average Daily Low Temperature 16.0°C (Long term average 12.9°C)
Total Precipitation 155.6 mm (Long term average 83.9 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)

Thursday, August 4, 2016

July 2016 Summary

Another hot and dry month

At over one and half degrees above average, it was definitely a hot month. 

With not much else so say about the heat this month let’s have a couple of fun facts for the summer so far: 

The last time the daily high temperature was more than 5 degrees below average was back on June 13th. So far we have seen 22 days above 30 degrees, on average we only see 8 of them during a typical year, but we still have a long way to go to beat the record of 49 back in 1955. 

For the third month in a row the precipitation was below average.  Although it might have been much worse as it was only in the last week of the month that we saw almost 40 mm of the 70 mm precipitation for July.  But as was typical of the type of storms we have seen this summer, most of the rain fell in short bursts lasting less than an hour, and this means a lot of it probably ran off without having time to soak into the ground.

The total precipitation for the year (485.0 mm) has now started to drop below the average for this time of the year (509.0 mm).

Summary for July 2016:
Maximum Temperature 33.4°C
Minimum Temperature 8.6°C
Average Daily High Temperature 28.1°C (Long term average 26.0°C)
Average Daily Low Temperature 15.1°C (Long term average 14.0°C)
Total Precipitation 70.2 mm (Long term average 98.6 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)

Sunday, July 3, 2016

June 2016 Summary

A dry and warm-ish June

We saw a lot of hot days in June, in fact the average daily high temperatures were the highest in almost 10 years. But the generally clear skies allowed the nighttime temperatures to dip down causing the average daily low temperatures to be the lowest in 12 years.

Put that all together and the overall temperature was a little over half a degree above the 1981-2010 average. But I put “warm-ish” in the headline as this still puts June within the average range.

For the second month in a row it was much drier than average, which is really starting to have an effect on the lawns and gardens of the region. Of the 55.2 mm that fell in June, half of it came during a couple of days early in the month meaning the rest of it was very dry.

The total precipitation for the first half of the year so far of 415.0 mm is incredibly close to the average for this time of the year of 416.1 mm.

Summary for June 2016:
Maximum Temperature 31.5°C
Minimum Temperature 5.2°C
Average Daily High Temperature 25.2°C (Long term average 23.6°C)
Average Daily Low Temperature 11.0°C (Long term average 11.5°C)
Total Precipitation 55.2 mm (Long term average 82.4 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)

Friday, June 3, 2016

May 2016 Summary

A dry and warm May 

Although it was just pretty much average for the first half of the month, it was hot enough in the second half to put the overall temperature for May at 1.2 degrees higher than average.  A neat thing you can see on the graph is the temperature starting at 24.7°C on the 12th and then going pretty much straight down to 0.9°C on the 15th.

As sometimes happens in the region, there were no below zero temperatures during the month of May.  So this makes the last frost day April 30, which is about 5 days earlier than the UW weather station average of May 6.  This is an instance where I don’t like using the Waterloo Wellington Airport data as a small difference in temperature can make the difference between a frost or non-frost day.  Indeed this May the airport did record a low of -1.0°C on the 9th, where we only got down to 0.6°C.

For the first time since September, it was a drier than average month.  With the 42.2 mm of precipitation in May only being a bit more than half of the average of 82.3 mm.  This has pretty much wiped out the surplus we have seen since the beginning of the year, so the total for the year of 359.8 mm is now just a little above the average of 342.4 mm.

Summary for May 2016:
Maximum Temperature 30.9°C
Minimum Temperature 0.6°C
Average Daily High Temperature 20.0°C (Long term average 18.7°C)
Average Daily Low Temperature 7.4°C (Long term average 6.4°C)
Total Precipitation 42.2 mm (Long term average 82.3 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)