| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
15.4 °C (+2.1) |
05:59 |
15.3 °C (+1.2) |
17.9 °C (+4.6), 2019 |
10.7 °C (-2.6), 2023 |
| Maximum Temperature |
24.2 °C (+2.6) |
13:07 |
27.1 °C (+4.6) |
28.2 °C (+6.6), 2024 |
18.3 °C (-3.3), 2020 |
| Mean Temperature |
19.5 °C (+2.3) |
|
21.2 °C (+2.9) |
22.0 °C, 2017 |
14.7 °C, 2020 |
| Minimum Humidity |
48% |
12:34 |
39% |
71%, 2016 |
39%, 2013 |
| Maximum Humidity |
89% |
06:35 |
80% |
94%, 2014 |
84%, 2009 |
| Mean Humidity |
73% |
|
59% |
85%, 2020 |
61%, 2017 |
| Minimum Pressure |
1007 hPa |
13:57 |
1015 hPa |
1026 hPa, 2021 |
1000 hPa, 2020 |
| Maximum Pressure |
1010 hPa |
23:56 |
1020 hPa |
1028 hPa, 2021 |
1004 hPa, 2020 |
| Mean Pressure |
1008 hPa |
|
1017 hPa |
1027 hPa, 2021 |
1002 hPa, 2020 |
| Mean Wind Speed |
6.4 mph (+2.4) |
|
4.0 mph (+0.0) |
7.6 mph, 2009 |
1.7 mph, 2013 |
| Maximum Wind Speed |
16.4 mph |
17:44 |
12.4 mph |
18.4 mph, 2009 |
5.9 mph, 2013 |
| Maximum Gust |
26.5 mph |
14:15 |
19.4 mph |
27.6 mph, 2009 |
7.6 mph, 2013 |
| Mean Wind Direction |
W |
|
|
|
|
| Rainfall |
0.4 mm |
|
6.8 mm (14%) |
2.8 mm, 2020 |
|
| Maximum Hourly Rain |
0.2 mm |
|
|
2.0 mm, 2020 |
|
| Maximum 10-min Rain |
0.2 mm |
|
|
1.4 mm, 2009 |
|
| Maximum Rain Rate |
n/a |
|
|
24, 2014 |
|
| Minimum Dew Point |
12.2 °C |
12:37 |
9.6 °C |
14.2 °C, 2016 |
6.5 °C, 2010 |
| Maximum Dew Point |
15.8 °C |
20:52 |
14.8 °C |
18.3 °C, 2024 |
11.0 °C, 2010 |
| Mean Dew Point |
14.2 °C |
|
12.3 °C |
15.4 °C, 2016 |
8.9 °C, 2010 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
15.4 °C |
06:00 |
15.3 °C |
18.8 °C, 2019 |
10.7 °C, 2023 |
| Day Maximum (09-21) |
24.2 °C |
13:07 |
27.1 °C |
28.2 °C, 2024 |
18.3 °C, 2020 |
| Max 10m Temp Rise |
0.7 °C |
11:41 |
0.8 °C |
0.9 °C, 2024 |
0.3 °C, 2018 |
| Max 1hr Temp Rise |
2.3 °C |
12:27 |
2.9 °C |
3.5 °C, 2024 |
1.3 °C, 2014 |
| Max 1hr Hum Rise |
17% |
15:25 |
12% |
17%, 2026 |
4%, 2016 |
| Max 10m Temp Fall |
1.6 °C |
15:17 |
0.8 °C |
1.6 °C, 2026 |
0.4 °C, 2014 |
| Max 1hr Temp Fall |
2.1 °C |
15:20 |
2.4 °C |
2.6 °C, 2013 |
1.1 °C, 2016 |
| Max 1hr Hum Fall |
15% |
12:02 |
12% |
17%, 2017 |
6%, 2016 |
| Max 10m Wind Speed |
12.2 mph |
17:52 |
9.1 mph |
13.8 mph, 2016 |
4.2 mph, 2013 |
| Minimum Feels-like |
18.3 °C |
05:42 |
17.1 °C |
21.5 °C, 2019 |
11.5 °C, 2010 |
| Maximum Feels-like |
27.6 °C |
15:10 |
29.9 °C |
34.4 °C, 2024 |
19.7 °C, 2010 |
| Mean Feels-like |
23.0 °C |
|
23.8 °C |
25.1 °C, 2017 |
15.8 °C, 2010 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
1 |
03:07 |
3 |
1, 2026 |
0, 2021 |
| Maximum PM2.5 |
11 |
21:10 |
14 |
11, 2026 |
11, 2026 |
| Mean PM2.5 |
4 |
|
6 |
4, 2026 |
4, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
8.8 °C (+0.4) |
11.9 °C (+3.4) |
14.6 °C (+6.2), 2024 |
3.3 °C (-5.1), 2016 |
| Humidity Range |
41% |
41% |
54%, 2013 |
13%, 2016 |
| Pressure Range |
3 hPa |
5 hPa |
10 hPa, 2015 |
2 hPa, 2021 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0 [0%] | 261 hrs (155%) [70%] |
11 [87%], 2017 |
0 [0%], 2026 |
| Wet Hours |
2 [Mean rain rate: 0.2 mm/h] | 13 hrs (38%) [1.9%] |
3, 2014 |
0, 2011 |
| 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 |
19.5 °C |