| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
17.8 °C (+6.0) |
05:01 |
14.3 °C (+2.0) |
17.8 °C (+6.0), 2026 |
6.1 °C (-5.7), 2024 |
| Maximum Temperature |
22.8 °C (+3.4) |
11:57 |
22.4 °C (+2.1) |
32.0 °C (+12.6), 2016 |
16.3 °C (-3.1), 2009 |
| Mean Temperature |
19.8 °C (+4.7) |
|
18.2 °C (+2.0) |
24.8 °C, 2016 |
10.9 °C, 2024 |
| Minimum Humidity |
74% |
11:58 |
54% |
91%, 2013 |
36%, 2016 |
| Maximum Humidity |
90% |
22:06 |
86% |
98%, 2013 |
78%, 2011 |
| Mean Humidity |
86% |
|
72% |
96%, 2013 |
62%, 2016 |
| Minimum Pressure |
1022 hPa |
05:44 |
1016 hPa |
1030 hPa, 2019 |
993 hPa, 2017 |
| Maximum Pressure |
1024 hPa |
23:40 |
1022 hPa |
1037 hPa, 2019 |
1002 hPa, 2017 |
| Mean Pressure |
1023 hPa |
|
1019 hPa |
1034 hPa, 2019 |
999 hPa, 2017 |
| Mean Wind Speed |
4.4 mph (+0.5) |
|
5.0 mph (+1.1) |
10.2 mph, 2017 |
2.1 mph, 2018 |
| Maximum Wind Speed |
10.5 mph |
15:38 |
13.6 mph |
24.2 mph, 2017 |
7.8 mph, 2013 |
| Maximum Gust |
26.5 mph |
01:12 |
23.1 mph |
41.5 mph, 2017 |
12.7 mph, 2013 |
| Mean Wind Direction |
WNW |
|
|
|
|
| Rainfall |
3.4 mm |
|
25.2 mm (116%) |
32.0 mm, 2013 |
|
| Maximum Hourly Rain |
2.4 mm |
13:27 |
|
9.0 mm, 2013 |
|
| Maximum 10-min Rain |
1.2 mm |
13:08 |
|
2.2 mm, 2013 |
|
| Maximum Rain Rate |
14 mm/h |
13:02 |
|
42 mm/h, 2013 |
|
| Minimum Dew Point |
15.2 °C |
00:10 |
10.6 °C |
15.2 °C, 2026 |
4.1 °C, 2024 |
| Maximum Dew Point |
19.4 °C |
14:07 |
15.2 °C |
19.4 °C, 2026 |
8.6 °C, 2024 |
| Mean Dew Point |
17.3 °C |
|
12.9 °C |
17.3 °C, 2026 |
5.9 °C, 2024 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
17.8 °C |
05:05 |
14.7 °C |
17.8 °C, 2026 |
6.1 °C, 2024 |
| Day Maximum (09-21) |
22.8 °C |
11:57 |
22.2 °C |
32.2 °C, 2016 |
16.3 °C, 2009 |
| Max 10m Temp Rise |
0.5 °C |
10:31 |
0.6 °C |
1.1 °C, 2016 |
0.2 °C, 2013 |
| Max 1hr Temp Rise |
1.9 °C |
11:13 |
2.2 °C |
3.9 °C, 2018 |
0.8 °C, 2013 |
| Max 1hr Hum Rise |
10% |
13:10 |
8% |
32%, 2019 |
3%, 2013 |
| Max 10m Temp Fall |
0.6 °C |
15:56 |
0.6 °C |
1.6 °C, 2017 |
0.3 °C, 2010 |
| Max 1hr Temp Fall |
1.5 °C |
13:13 |
1.8 °C |
2.9 °C, 2024 |
0.9 °C, 2010 |
| Max 1hr Hum Fall |
7% |
11:21 |
10% |
22%, 2017 |
1%, 2013 |
| Max 10m Wind Speed |
8.3 mph |
15:45 |
10.0 mph |
18.4 mph, 2017 |
5.8 mph, 2024 |
| Minimum Feels-like |
22.3 °C |
05:01 |
16.2 °C |
23.4 °C, 2016 |
2.9 °C, 2024 |
| Maximum Feels-like |
29.3 °C |
14:12 |
25.7 °C |
36.9 °C, 2016 |
16.6 °C, 2024 |
| Mean Feels-like |
25.4 °C |
|
21.1 °C |
29.6 °C, 2016 |
10.3 °C, 2024 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
1 |
12:35 |
1 |
1, 2026 |
0, 2021 |
| Maximum PM2.5 |
64 |
14:15 |
15 |
64, 2026 |
64, 2026 |
| Mean PM2.5 |
6 |
|
4 |
6, 2026 |
6, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
5.0 °C (-2.6) |
8.1 °C (+0.0) |
14.3 °C (+6.7), 2016 |
4.3 °C (-3.3), 2022 |
| Humidity Range |
16% |
33% |
56%, 2018 |
7%, 2013 |
| Pressure Range |
2 hPa |
6 hPa |
10 hPa, 2015 |
2 hPa, 2009 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0.5 [4%] | 69 hrs (103%) [44%] |
11.6 [100%], 2019 |
0 [0%], 2013 |
| Wet Hours |
4 [Mean rain rate: 0.8 mm/h] | 24 hrs (135%) [7.7%] |
15, 2013 |
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 |
18.0 °C |