Significantly cooler than normal.
Wetter than normal but not by much - and only because of one very wet day.
At least two widespread ground frosts.

Average temperature = 10.9°C; diff from climate av: -1.5°C
Average humidity = 88%
Average dewpoint = 8.9°C
Average barometer = 1016.1 mb
Average windspeed = 5.4 mph
Average gustspeed = 7.6 mph
Average direction = 293° (WNW)
Rainfall for month = 73.6 mm (+26mm)
Rainfall for year = 421.2 mm (-190mm)
Maximum rain per minute = 0.6 mm on day 15 at time 02:27
Maximum temperature = 18.8°C on day 10 at time 14:32
Minimum temperature = 1.1°C on day 27 at time 07:33
Maximum humidity = 98% on day 19 at time 09:25
Minimum humidity = 55% on day 19 at time 14:02
Maximum dewpoint = 14.5°C on day 12 at time 13:52
Minimum dewpoint = 0.4°C on day 27 at time 7:33
Maximum pressure = 1038.8 mb on day 28 at time 10:00
Minimum pressure = 988.5 mb on day 15 at time 05:27
Maximum windspeed = 27.6 mph from 338°(NNW) on day 04 at time 11:19
Maximum gust speed = 40.3 mph from 338°(NNW) on day 04 at time 11:18
Maximum heat index = 18.8°C on day 10 at time 14:32
Avg daily max temp :15.0°C
Avg daily min temp :6.6°C
Growing degrees days :73.3 GDD
Total windrun = 3338.0miles
-----------------------------------
Daily rain totals
-----------------------------------
00.2 mm on day 1
02.0 mm on day 2
03.8 mm on day 3
04.4 mm on day 4
01.4 mm on day 5
00.2 mm on day 8
00.2 mm on day 9
00.2 mm on day 11
06.8 mm on day 12
00.8 mm on day 14
48.4 mm on day 15
01.0 mm on day 18
01.4 mm on day 21
02.4 mm on day 22
00.4 mm on day 24

As for the CET area coldest September in these parts since 1993 but nowhere near as cold as 1986.

                   Monthly Climatological Summary for Sep 2015

Name: hillcrest   City: Peasedown St John   State: N.E.Somerset UK.
Elevation: 159 m  Lat: N 51° 18' 60"   Lon: W 002° 25' 15"

                  Temperature (°C), Rain (mm), Wind Speed (km/h)

                                      Heat  Cool        Avg
    Mean                              Deg   Deg         Wind                 Dom
Day Temp  High   Time   Low    Time   Days  Days  Rain  Speed High   Time    Dir
----------------------------------------------------------------------------------
 1  15.0  22.4   07:57   9.0   06:27   3.7   0.4   0.3   2.9  15.0   11:53     N
 2  13.5  21.7   13:31   8.0   05:56   5.0   0.3   0.0   2.5  15.0   11:08     N
 3  12.6  18.7   10:47   8.7   01:56   5.7   0.0   0.0   2.8  15.0   11:39     N
 4  13.6  19.1   15:13  10.3   23:56   4.7   0.0   0.0   3.1  17.0   17:22     N
 5  12.7  16.2   10:56   9.6   23:57   5.7   0.0   0.0   7.0  21.0   12:48   NNE
 6  14.0  21.7   11:32   6.8   05:57   4.7   0.4   0.0   1.3  10.0   10:40     N
 7  14.7  20.5   13:36   7.7   06:26   3.9   0.3   0.0   4.0  13.0   15:04    NE
 8  11.9  15.9   14:13   8.0   06:57   6.4   0.0   0.0   5.4  18.0   10:45   ENE
 9  13.8  18.3   16:39   9.0   03:57   4.4   0.0   0.0   6.0  24.0   12:25     E
10  15.3  23.1   13:44  10.1   05:27   3.9   0.9   0.0   5.1  30.0   12:32     E
11  15.5  22.0   12:32  10.5   05:57   3.4   0.6   0.3   5.0  27.0   11:57   ESE
12  14.5  18.0   11:59  11.1   20:56   3.8   0.0   4.8   2.5  16.0   15:57   SSE
13  13.7  20.5   11:58  10.6   06:56   4.7   0.1   2.7   3.8  19.0   15:46     E
14  11.7  18.6   11:27   9.5   22:57   6.7   0.0  24.3   3.5  17.0   13:49     E
15  12.6  17.5   14:26   8.6   03:57   5.8   0.0   3.9   2.7  15.0   08:46   SSE
16  11.5  15.4   13:57   8.6   06:56   6.7   0.0  15.9   7.5  22.0   12:06    NE
17  12.8  19.2   13:37   8.2   06:57   5.6   0.0   1.5   1.1  11.0   00:27   ENE
18  14.4  20.5   14:01  10.6   06:27   4.0   0.2   0.3   2.6  12.0   10:58     N
19  14.3  22.0   13:40   8.5   06:28   4.4   0.4   0.3   0.8  10.0   11:53   NNE
20  14.1  21.5   11:35  10.4   02:28   4.4   0.2   0.0   1.0   9.0   11:06     E
21  12.5  15.7   14:58  10.2   23:58   5.8   0.0   2.7   3.1  18.0   17:05     E
22  11.6  15.4   11:03   9.1   05:58   6.8   0.0   7.8   4.9  23.0   12:03   NNW
23  13.4  20.6   09:40   8.0   06:28   5.0   0.1   0.3   1.4 190.0   13:28     E
24  13.6  18.5   12:24  10.7   23:27   4.8   0.0   5.4   2.8 213.0   15:50     E
25  13.0  20.7   09:49   8.8   06:57   5.5   0.1   0.0   1.6  12.0   10:28     N
26  11.9  17.9   14:30   6.6   06:27   6.4   0.0   0.0   3.1  13.0   12:00   ENE
27  12.4  18.6   14:16   6.2   06:57   5.9   0.0   0.0   5.2  19.0   12:52     E
28  12.7  19.2   13:52   8.0   05:28   5.6   0.0   0.0   5.3  22.0   11:46     E
29  13.5  18.9   14:00   8.9   06:28   4.9   0.0   0.0   7.0  23.0   16:01     E
30  12.9  18.0   13:36   9.2   06:57   5.5   0.0   0.0   9.3  32.0   13:44     E
----------------------------------------------------------------------------------
    13.3  23.1    10     6.2    27   153.8   4.0  70.5   3.8 213.0    24     ENE

Max >=  27.0:  0
Max <=   0.0:  0
Min <=   0.0:  0
Min <= -18.0:  0
Max Rain: 24.3 on day 14
Days of Rain: 14 (>= 0.2 mm)  8 (>= 2.0 mm)  1 (>= 20.0 mm)
Heat Base: 18.3  Cool Base: 18.3  Method: Integration