| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
12.6 °C (-0.5) |
23:55 |
11.9 °C (-0.1) |
18.3 °C (+5.2), 2025 |
8.5 °C (-4.6), 2014 |
| Maximum Temperature |
19.8 °C (-2.3) |
17:39 |
22.3 °C (+1.3) |
33.2 °C (+11.1), 2025 |
17.6 °C (-4.5), 2021 |
| Mean Temperature |
15.8 °C (-1.4) |
|
17.3 °C (+0.6) |
26.4 °C, 2025 |
14.7 °C, 2021 |
| Minimum Humidity |
57% |
18:27 |
51% |
70%, 2021 |
24%, 2015 |
| Maximum Humidity |
88% |
23:37 |
89% |
95%, 2014 |
72%, 2010 |
| Mean Humidity |
76% |
|
70% |
82%, 2021 |
45%, 2015 |
| Minimum Pressure |
1012 hPa |
02:53 |
1015 hPa |
1024 hPa, 2011 |
999 hPa, 2017 |
| Maximum Pressure |
1016 hPa |
23:55 |
1019 hPa |
1026 hPa, 2011 |
1010 hPa, 2016 |
| Mean Pressure |
1013 hPa |
|
1017 hPa |
1025 hPa, 2011 |
1004 hPa, 2017 |
| Mean Wind Speed |
2.6 mph (-1.8) |
|
3.9 mph (-0.5) |
8.5 mph, 2012 |
1.8 mph, 2014 |
| Maximum Wind Speed |
10.4 mph |
14:50 |
12.0 mph |
20.5 mph, 2016 |
9.0 mph, 2014 |
| Maximum Gust |
19.4 mph |
01:12 |
19.8 mph |
27.7 mph, 2012 |
12.1 mph, 2014 |
| Mean Wind Direction |
SW |
|
|
|
|
| Rainfall |
7.0 mm |
|
27.8 mm (59%) |
7.0 mm, 2022 |
|
| Maximum Hourly Rain |
6.8 mm |
19:57 |
|
6.8 mm, 2022 |
|
| Maximum 10-min Rain |
6.3 mm |
19:06 |
|
6.3 mm, 2022 |
|
| Maximum Rain Rate |
90 mm/h |
19:03 |
|
90 mm/h, 2022 |
|
| Minimum Dew Point |
10.0 °C |
18:27 |
9.0 °C |
14.5 °C, 2025 |
4.8 °C, 2011 |
| Maximum Dew Point |
12.8 °C |
19:27 |
13.6 °C |
18.8 °C, 2025 |
9.5 °C, 2011 |
| Mean Dew Point |
11.5 °C |
|
11.4 °C |
16.5 °C, 2025 |
6.8 °C, 2011 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 13.9 °C * |
05:31 |
12.2 °C |
18.3 °C, 2025 |
8.5 °C, 2014 |
| Day Maximum (09-21) |
19.8 °C |
17:39 |
22.3 °C |
33.2 °C, 2025 |
17.6 °C, 2021 |
| Max 10m Temp Rise |
0.7 °C |
16:19 |
0.7 °C |
0.9 °C, 2018 |
0.3 °C, 2021 |
| Max 1hr Temp Rise |
1.6 °C |
16:50 |
2.5 °C |
3.3 °C, 2015 |
1.3 °C, 2021 |
| Max 1hr Hum Rise |
28% |
19:27 |
11% |
28%, 2022 |
6%, 2021 |
| Max 10m Temp Fall |
1.3 °C |
19:09 |
0.6 °C |
1.6 °C, 2009 |
0.3 °C, 2016 |
| Max 1hr Temp Fall |
3.6 °C |
19:23 |
2.0 °C |
3.6 °C, 2022 |
0.9 °C, 2020 |
| Max 1hr Hum Fall |
10% |
17:02 |
12% |
17%, 2014 |
6%, 2020 |
| Max 10m Wind Speed |
8.7 mph |
14:57 |
9.3 mph |
16.4 mph, 2016 |
0.0 mph, 2024 |
| Minimum Feels-like |
14.2 °C |
23:52 |
12.8 °C |
22.0 °C, 2025 |
8.6 °C, 2011 |
| Maximum Feels-like |
21.9 °C |
17:37 |
25.0 °C |
39.7 °C, 2025 |
20.2 °C, 2021 |
| Mean Feels-like |
17.8 °C |
|
19.3 °C |
31.4 °C, 2025 |
15.9 °C, 2014 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
7.2 °C (-1.9) |
10.4 °C (+1.5) |
15.9 °C (+6.8), 2015 |
4.9 °C (-4.2), 2021 |
| Humidity Range |
31% |
38% |
57%, 2009 |
20%, 2020 |
| Pressure Range |
4 hPa |
4 hPa |
11 hPa, 2017 |
2 hPa, 2011 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
4 [27%] | 214 hrs (111%) [47%] |
15 [99%], 2015 |
0.3 [2%], 2020 |
| Wet Hours |
1 [Mean rain rate: 7 mm/h] | 25 hrs (68%) [3.5%] |
3, 2016 |
0, 2009 |
| Cloud Cover |
unknown |
| Events |
None |
| Comments |
Torrential sh |
| Extra Comments |
|
| Issues |
webcam disk full - missing images |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
20.0 °C |