| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
11.6 °C (-2.5) |
23:41 |
14.0 °C (-0.3) |
20.0 °C (+5.9), 2012 |
11.4 °C (-2.7), 2014 |
| Maximum Temperature |
17.1 °C (-5.3) |
13:17 |
22.4 °C (-0.5) |
30.0 °C (+7.6), 2012 |
17.1 °C (-5.3), 2011 |
| Mean Temperature |
13.7 °C (-3.9) |
|
18.0 °C (-0.4) |
25.0 °C, 2012 |
13.7 °C, 2011 |
| Minimum Humidity |
62% |
13:34 |
48% |
72%, 2023 |
40%, 2012 |
| Maximum Humidity |
93% |
21:00 |
84% |
95%, 2022 |
71%, 2015 |
| Mean Humidity |
82% |
|
67% |
86%, 2023 |
53%, 2012 |
| Minimum Pressure |
1013 hPa |
17:10 |
1009 hPa |
1020 hPa, 2018 |
1003 hPa, 2019 |
| Maximum Pressure |
1017 hPa |
12:00 |
1015 hPa |
1024 hPa, 2025 |
1010 hPa, 2010 |
| Mean Pressure |
1015 hPa |
|
1012 hPa |
1022 hPa, 2025 |
1006 hPa, 2019 |
| Mean Wind Speed |
4.9 mph (+0.9) |
|
4.8 mph (+0.8) |
6.3 mph, 2017 |
2.3 mph, 2024 |
| Maximum Wind Speed |
13.5 mph |
|
12.6 mph |
16.1 mph, 2019 |
8.8 mph, 2024 |
| Maximum Gust |
19.4 mph |
09:38 |
17.9 mph |
26.5 mph, 2019 |
13.5 mph, 2024 |
| Mean Wind Direction |
NNE |
|
|
|
|
| Rainfall |
14.6 mm |
|
39.2 mm (125%) |
14.6 mm, 2011 |
|
| Maximum Hourly Rain |
9.3 mm |
16:19 |
|
9.9 mm, 2017 |
|
| Maximum 10-min Rain |
3.3 mm |
15:48 |
|
5.9 mm, 2017 |
|
| Maximum Rain Rate |
60 mm/h |
15:46 |
|
84 mm/h, 2023 |
|
| Minimum Dew Point |
9.6 °C |
06:43 |
8.6 °C |
15.6 °C, 2022 |
5.6 °C, 2014 |
| Maximum Dew Point |
11.5 °C |
17:45 |
14.1 °C |
18.6 °C, 2023 |
10.5 °C, 2014 |
| Mean Dew Point |
10.5 °C |
|
11.3 °C |
17.2 °C, 2023 |
8.6 °C, 2014 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 13.0 °C * |
04:15 |
14.1 °C |
20.0 °C, 2012 |
11.4 °C, 2014 |
| Day Maximum (09-21) |
17.1 °C |
13:15 |
22.4 °C |
30.0 °C, 2012 |
17.1 °C, 2011 |
| Max 10m Temp Rise |
0.3 °C |
08:27 |
0.6 °C |
0.8 °C, 2017 |
0.3 °C, 2011 |
| Max 1hr Temp Rise |
1.3 °C |
11:24 |
2.1 °C |
2.8 °C, 2010 |
1.0 °C, 2018 |
| Max 1hr Hum Rise |
14% |
14:34 |
9% |
20%, 2017 |
4%, 2021 |
| Max 10m Temp Fall |
0.7 °C |
13:54 |
0.6 °C |
2.9 °C, 2017 |
0.2 °C, 2015 |
| Max 1hr Temp Fall |
2.1 °C |
14:40 |
1.9 °C |
4.4 °C, 2017 |
0.6 °C, 2015 |
| Max 1hr Hum Fall |
12% |
11:42 |
12% |
15%, 2016 |
6%, 2015 |
| Max 10m Wind Speed |
9.0 mph |
11:51 |
8.4 mph |
12.3 mph, 2019 |
6.1 mph, 2009 |
| Minimum Feels-like |
13.0 °C |
23:25 |
15.5 °C |
22.9 °C, 2012 |
11.5 °C, 2014 |
| Maximum Feels-like |
18.7 °C |
12:22 |
24.7 °C |
34.9 °C, 2012 |
18.7 °C, 2011 |
| Mean Feels-like |
15.3 °C |
|
20.0 °C |
28.7 °C, 2012 |
15.3 °C, 2011 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
5.5 °C (-2.8) |
8.3 °C (-0.2) |
10.0 °C (+1.7), 2012 |
4.9 °C (-3.4), 2015 |
| Humidity Range |
31% |
35% |
50%, 2010 |
20%, 2018 |
| Pressure Range |
4 hPa |
6 hPa |
9 hPa, 2023 |
2 hPa, 2020 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0 [0%] | 79 hrs (72%) [32%] |
12 [91%], 2012 |
0 [0%], 2011 |
| Wet Hours |
2.5
[Mean rain rate: 6 mm/h] | 19 hrs (85%) [4.3%] |
3, 2019 |
0, 2009 |
| Cloud Cover |
Overcast |
| Events |
None |
| Comments |
1330-19 Heavy Showers (16 Torrential) |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
0.0 °C |
