Summer Index rating for Manchester

[summer '95]

I have calculated the summer index rating for Summer 2004 in Manchester.

Summer 2004 had a rating of 196, the lowest value since 1998 which had a value of 192.

The high mean temperatures of June and August saved the summer from having a lower index rating.

The rating for an average summer in Manchester is 212.

The highest rating was 301 for summer 1976

The lowest rating was 143 for summer 1954

[Thundery wintry showers]

Interesting stats there. I suspect the extremely heavy August rainfall will almost certainly have contributed to this!

As for the stats for Lancaster and for Tyneside, the following appear to be the case:

In Lancaster, the summer had a 10% shortage of sunshine in each of the months. However, summers 1998 and 2002 were both markedly duller with overall deficits of 20-30%. The summer was also the wettest since 1998 and the coolest since 2002.

However, one factor which I doubt gets included in the summer index is storm activity. Statistically, Lancaster's summer was the thunderiest overall since 1994, and the second thunderiest since at least the early Eighties.

As for Tyneside, the summer had 10-20% less sun than normal, but summers 1998, 2000 and 2002 were duller. The summer was also the wettest since at least 1987. Thunder activity was near normal, and was the lowest since 2001.

[summer '95]

Interesting stats there.  I suspect the extremely heavy August rainfall will almost certainly have contributed to this!

Actually the index rating doesn't take into account of the amount of rain that has fallen but the number of rain days i.e. the number of days where rainfall was recorded.

This takes into account to how rainfall totals can distort figures.

eg 140mm of rain was recorded during August 1981 but 95mm of that fell in one day and there were 23 days where no rain was recorded.

[J10]

How exactly is the summer index calculated. :?:

[summer '95]

How exactly is the summer index calculated.  :?:

Summer index = 10x [(mean max temperature) + (total sunshine/67) - (number of rain days/8]

[Thundery wintry showers]

I like the use of mean max temperature- in my experience it usually says a lot more about the summer than the mean minimum temperature.

I personally find maximum temperature a particularly good index for the north, for I tend to find that up here, the higher the maximum temperature, the better. This wouldn't be the case down south where I'd be almost certain to find the warmest summers uncomfortably hot.

Incidentally I wonder how the figures work, as I can't get the same results using the long-term averages for Ringway (maybe you use a different Manchester station though)

For 1961-90 I got an average figure of 195, and for 1971-2000 I got 199, not 212. This was calculated by getting meam maxima of 191 and 195 for the respective periods, 8 for the sunshine, and 4 for the raindays.

I was using (mean maximum temperature over the three months)+(total summer sunshine over the three months/67)-(total raindays over the three months/8 ) to get those figures- I presume I was doing something wrong.

This isn't criticising the index, more wondering how it works as I'm very interested in statistics myself.

[summer '95]

The average 212 was actually not derived from using 30 year averages but over a longer period of time of readings of mean max temperatures, rain days and sunshine right back to 1901.