Wednesday, September 23, 2009

Summer 2009 summary

An average summer for both temperature and precipitation

This summary would have been a lot different if we used meteorological summer (June, July, August) rather than astronomical summer (summer solstice to autumnal equinox). The weather in these first 3 weeks of September has been quite a contrast to the rest of the summer.

It was cold in July, average in August and warm in September, this all balanced out to an overall temperature just 0.1 degrees less than average. Obviously this is within the average range.

We were pretty much average for precipitation at the beginning of September, but only managed to barely stay in the average range by the end of the summer. We were saved by 11.0 mm on the very last full day of summer, following 20 days without any significant precipitation.

I think that people can be forgiven for thinking that the summer was wetter than it really was as there was only a single weekend during July and August where both Saturday and Sunday had above average temperatures and no rain (August 15-16).

But even this couldn't dampen the opinions people had about the summer. In a very unscientific poll conducted on the UW weather station website the 267 votes broke down as follows: 41% thought it was great(112 Votes), 25% had it as good(67 Votes), for 8% it was just OK(23 Votes), 11% considered it bad(31 Votes), while 12% called it total washout(34 Votes). The "great" category was down from 51% last year, but with all the complaining I heard about this summer I'm still a little surprised that a plurality of people said the summer was either good or great.

Summary for Summer 2009:
Maximum Temperature 31.3 °C
Minimum Temperature 1.9 °C
Average Daily High Temperature 23.5 °C (Long term average 24.2 °C)
Average Daily Low Temperature 12.7 °C (Long term average 12.2 °C)
Total Precipitation 206.9 mm (Long term average 274.0 mm)

(Long term averages based on 1970-2000 data for the Waterloo Wellington Airport)

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Pooya said...

I'm really surprised that the majority thought we had a good summer. Like you mentioned, we only had a single "summer" weekend and for someone like me whose indoors 8 hours a day, this summer was a total washout with some good days here and there.

We had some !COLD! nights too! I'm not a big fan of the heat, but I definately wouldn't mind warm weekends to hit the beach or go camping.

Pete Whittington said...

Thanks for the write-up Frank. I was trying to think of a way to represent the summer with the cold/wet persona it had. Just simply looking at the averages made us all look like whiners 

Your point about the weekends was great; as these are the days we are most interested in good weather.

I was wondering if there is any sort of official way/statistic to keep track of ‘rain days’. For instance, there’s a big difference to the quality of a summer if it rains hard once a week at 20 mm/storm vs. showers 5 separate days a week at 4mm/storm (i.e., 20 mm/week, same as the big storm) for a seasonal total of 240 mm/12 weeks. Does such a variable exist or is tracked?

Looking at the precipitation trend in the summary it looked like we had lots of little rain events, rather than a few big rain events. Does this get quantified somehow?

Most of us, I think, would prefer the big summer thunderstorms to get it over and done with each week – though basements and plants may not.