| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
12.8 °C (+0.5) |
23:59 |
14.6 °C (+2.1) |
17.4 °C (+5.1), 2023 |
6.9 °C (-5.4), 2019 |
| Maximum Temperature |
18.1 °C (-2.3) |
00:22 |
22.9 °C (+2.1) |
29.7 °C (+9.3), 2023 |
16.0 °C (-4.4), 2015 |
| Mean Temperature |
15.3 °C (-0.9) |
|
18.8 °C (+2.1) |
23.2 °C, 2023 |
12.1 °C, 2019 |
| Minimum Humidity |
64% |
00:12 |
52% |
80%, 2022 |
24%, 2012 |
| Maximum Humidity |
90% |
09:55 |
85% |
97%, 2022 |
82%, 2016 |
| Mean Humidity |
80% |
|
70% |
91%, 2022 |
54%, 2012 |
| Minimum Pressure |
1007 hPa |
14:02 |
1016 hPa |
1025 hPa, 2015 |
996 hPa, 2017 |
| Maximum Pressure |
1015 hPa |
00:11 |
1021 hPa |
1031 hPa, 2015 |
1007 hPa, 2017 |
| Mean Pressure |
1011 hPa |
|
1019 hPa |
1028 hPa, 2015 |
1000 hPa, 2017 |
| Mean Wind Speed |
4.0 mph (+0.1) |
|
5.4 mph (+1.5) |
6.6 mph, 2016 |
0.7 mph, 2024 |
| Maximum Wind Speed |
10.6 mph |
17:46 |
14.3 mph |
22.3 mph, 2016 |
5.9 mph, 2014 |
| Maximum Gust |
17.3 mph |
17:09 |
24.3 mph |
33.9 mph, 2016 |
7.6 mph, 2014 |
| Mean Wind Direction |
WNW |
|
|
|
|
| Rainfall |
15.8 mm |
|
17.8 mm (134%) |
15.8 mm, 2026 |
|
| Maximum Hourly Rain |
2.4 mm |
09:32 |
|
6.0 mm, 2024 |
|
| Maximum 10-min Rain |
0.6 mm |
06:55 |
|
4.1 mm, 2010 |
|
| Maximum Rain Rate |
3.6 mm/h |
12:13 |
|
50 mm/h, 2010 |
|
| Minimum Dew Point |
8.9 °C |
23:59 |
10.7 °C |
16.1 °C, 2023 |
4.0 °C, 2012 |
| Maximum Dew Point |
13.9 °C |
14:14 |
15.3 °C |
21.7 °C, 2023 |
8.9 °C, 2019 |
| Mean Dew Point |
11.8 °C |
|
12.9 °C |
18.6 °C, 2023 |
6.5 °C, 2019 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 14.2 °C * |
07:22 |
15.3 °C |
17.8 °C, 2016 |
6.9 °C, 2019 |
| Day Maximum (09-21) |
* 16.3 °C * |
17:27 |
22.6 °C |
29.7 °C, 2023 |
16.0 °C, 2015 |
| Max 10m Temp Rise |
0.6 °C |
17:18 |
0.6 °C |
1.2 °C, 2012 |
0.3 °C, 2011 |
| Max 1hr Temp Rise |
1.9 °C |
17:16 |
2.2 °C |
4.9 °C, 2012 |
1.0 °C, 2017 |
| Max 1hr Hum Rise |
9% |
02:44 |
8% |
16%, 2013 |
4%, 2020 |
| Max 10m Temp Fall |
0.7 °C |
14:26 |
0.6 °C |
1.4 °C, 2013 |
0.3 °C, 2015 |
| Max 1hr Temp Fall |
1.8 °C |
15:14 |
1.9 °C |
4.0 °C, 2012 |
1.1 °C, 2018 |
| Max 1hr Hum Fall |
11% |
17:26 |
10% |
18%, 2013 |
5%, 2015 |
| Max 10m Wind Speed |
7.3 mph |
01:50 |
10.5 mph |
17.7 mph, 2016 |
4.1 mph, 2014 |
| Minimum Feels-like |
13.6 °C |
23:59 |
16.6 °C |
22.1 °C, 2023 |
5.3 °C, 2019 |
| Maximum Feels-like |
20.1 °C |
02:44 |
26.3 °C |
38.2 °C, 2023 |
17.1 °C, 2015 |
| Mean Feels-like |
17.5 °C |
|
21.6 °C |
29.8 °C, 2023 |
11.8 °C, 2019 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
2 |
01:50 |
1 |
2, 2026 |
0, 2021 |
| Maximum PM2.5 |
13 |
23:45 |
10 |
13, 2026 |
13, 2026 |
| Mean PM2.5 |
4 |
|
4 |
4, 2026 |
4, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
5.3 °C (-2.8) |
8.2 °C (-0.0) |
17.2 °C (+9.1), 2012 |
5.3 °C (-2.8), 2022 |
| Humidity Range |
26% |
33% |
60%, 2012 |
17%, 2022 |
| Pressure Range |
8 hPa |
6 hPa |
11 hPa, 2017 |
2 hPa, 2023 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
2.6 [22%] | 41 hrs (98%) [42%] |
11.7 [98%], 2014 |
0.3 [3%], 2010 |
| Wet Hours |
13 [Mean rain rate: 1.2 mm/h] | 15 hrs (137%) [7.8%] |
13, 2026 |
0, 2009 |
| Cloud Cover |
unknown |
| Events |
None |
| Comments |
data is awaiting quality control from site operator |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
18.5 °C |