Summer temperature trend

An opportunity to discuss climatic change. Particularly welcome might be contributions from members who have long term records and can offer data for their specific location, whilst qualifying these with respect to changes to their site and local environment.
Post Reply
User avatar
Len Wood
Posts: 91
Joined: Sat Dec 12, 2015 8:41 pm
Location: 1 km from coast in Wembury, SW Devon

Summer temperature trend

Post by Len Wood » Wed Sep 21, 2016 9:31 am

No apparent trend over this time frame
summer trend.jpg
summer trend.jpg (78.41 KiB) Viewed 2932 times
Len
Wembury, SW Devon coast

83 m amsl

User avatar
Nicholas Gardner
Posts: 107
Joined: Sat Dec 12, 2015 8:11 pm
Location: Rural riverside valley location near the village of Newton Poppleford and 2 km from the sea.
Contact:

Re: Summer temperature trend

Post by Nicholas Gardner » Wed Sep 21, 2016 6:23 pm

Len, my record only goes back to 2005. I suspect the exceptionally warm summer of 2006 and then the very poor summers of 2007, 2008, 2011 & 2012 have had an influence somewhat. These wet/cool summers were rather exceptional (to me they were) and led to some of the worst summer weather I have ever experienced. Thankfully, since 2013 things seem to have reverted back to something more normal.
ottervalleysummermeantemp.png
ottervalleysummermeantemp.png (12.68 KiB) Viewed 2925 times
Otter Valley Weather
Near Newton Poppleford, Sidmouth - Devon
50:41N 3:17 W; 20 metres AMSL; Station Grade B-BAAA37
http://www.ottervalleyweather.me.uk

User avatar
Martin Rowley
Posts: 34
Joined: Sat Dec 12, 2015 8:32 pm
Location: West Moors, East Dorset

Re: Summer temperature trend

Post by Martin Rowley » Thu Sep 22, 2016 2:48 pm

... I maintain a couple of series which try to capture the 'goodness'/'badness' of summers based on sunshine and maxima - the two parameters that most people would judge a summer by. There's a lot of 'fudging' involved due to changes of equipment, locations, units of measurement etc., but I believe that the graphs below capture the broad trends OK.

As you can see [spot values are individual years/black line rolling 10-year mean ending at the tenth year], although recent summers continue the generally 'good' summers since the second-half of the 1980s, in recent years there has been a gentle downturn in values.
LondonSummerIndex_1900_LATEST.gif
LondonSummerIndex_1900_LATEST.gif (26.33 KiB) Viewed 2915 times
SouthWessexSummerIndex_1900_LATEST.gif
SouthWessexSummerIndex_1900_LATEST.gif (13.49 KiB) Viewed 2915 times
Martin Rowley
West Moors, East Dorset
Lat: 50deg 49.25'N, Long: 01deg 53.05'W
Height (amsl): 17 m (56 feet)
COL category: C1 overall/TRSHEUN=CC-A03-

User avatar
Len Wood
Posts: 91
Joined: Sat Dec 12, 2015 8:41 pm
Location: 1 km from coast in Wembury, SW Devon

Re: Summer temperature trend

Post by Len Wood » Fri Sep 23, 2016 9:52 pm

The longterm Plymouth record is broadly in agreement with your indices Martin.

There is a small longterm warming trend shown by the black dotted line.
The record is smoothed by 10 yr running means shown in red.
Three periods of relatively warm summers show up.
Just like your graphs, there is a small decrease in summer temperature in the last few years.
JJA trend.jpg
JJA trend.jpg (141.23 KiB) Viewed 2908 times
Len
Wembury, SW Devon coast

83 m amsl

Post Reply