| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
13.7 °C (+3.6) |
07:39 |
13.7 °C (+3.7) |
15.6 °C (+5.5), 2023 |
7.2 °C (-2.9), 2018 |
| Maximum Temperature |
20.7 °C (+3.9) |
14:41 |
20.7 °C (+4.0) |
27.1 °C (+10.3), 2011 |
13.3 °C (-3.5), 2024 |
| Mean Temperature |
16.8 °C (+3.7) |
|
16.8 °C (+3.9) |
19.3 °C, 2011 |
11.1 °C, 2018 |
| Minimum Humidity |
49% |
14:45 |
49% |
85%, 2024 |
40%, 2011 |
| Maximum Humidity |
89% |
04:28 |
89% |
98%, 2010 |
82%, 2009 |
| Mean Humidity |
72% |
|
72% |
91%, 2024 |
66%, 2018 |
| Minimum Pressure |
1016 hPa |
00:00 |
1016 hPa |
1029 hPa, 2015 |
993 hPa, 2020 |
| Maximum Pressure |
1030 hPa |
23:55 |
1030 hPa |
1033 hPa, 2015 |
1001 hPa, 2020 |
| Mean Pressure |
1023 hPa |
|
1023 hPa |
1031 hPa, 2015 |
998 hPa, 2020 |
| Mean Wind Speed |
3.8 mph (-0.3) |
|
3.8 mph (-0.3) |
7.2 mph, 2017 |
1.2 mph, 2011 |
| Maximum Wind Speed |
12.1 mph |
11:49 |
12.1 mph |
17.6 mph, 2022 |
8.1 mph, 2011 |
| Maximum Gust |
18.4 mph |
13:08 |
18.4 mph |
29.7 mph, 2021 |
10.0 mph, 2011 |
| Mean Wind Direction |
W |
|
|
|
|
| Rainfall |
0.8 mm |
|
0.8 mm (38%) |
17.6 mm, 2019 |
|
| Maximum Hourly Rain |
0.8 mm |
01:01 |
|
10.8 mm, 2019 |
|
| Maximum 10-min Rain |
0.8 mm |
00:24 |
|
7.0 mm, 2019 |
|
| Maximum Rain Rate |
7 mm/h |
00:18 |
|
92 mm/h, 2019 |
|
| Minimum Dew Point |
8.5 °C |
17:14 |
8.5 °C |
13.4 °C, 2023 |
2.7 °C, 2018 |
| Maximum Dew Point |
13.4 °C |
00:20 |
13.4 °C |
18.6 °C, 2023 |
6.4 °C, 2018 |
| Mean Dew Point |
11.3 °C |
|
11.3 °C |
16.1 °C, 2023 |
4.7 °C, 2018 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
13.7 °C |
07:38 |
13.7 °C |
15.6 °C, 2023 |
7.2 °C, 2018 |
| Day Maximum (09-21) |
20.7 °C |
14:41 |
20.7 °C |
27.1 °C, 2011 |
13.3 °C, 2024 |
| Max 10m Temp Rise |
0.5 °C |
11:01 |
0.5 °C |
0.9 °C, 2011 |
0.2 °C, 2010 |
| Max 1hr Temp Rise |
1.9 °C |
08:56 |
1.9 °C |
4.4 °C, 2011 |
0.6 °C, 2010 |
| Max 1hr Hum Rise |
13% |
01:03 |
13% |
15%, 2019 |
3%, 2023 |
| Max 10m Temp Fall |
0.6 °C |
00:41 |
0.6 °C |
1.2 °C, 2019 |
0.2 °C, 2010 |
| Max 1hr Temp Fall |
2.1 °C |
01:17 |
2.1 °C |
3.4 °C, 2019 |
0.3 °C, 2017 |
| Max 1hr Hum Fall |
11% |
13:07 |
11% |
20%, 2014 |
3%, 2024 |
| Max 10m Wind Speed |
8.8 mph |
14:10 |
8.8 mph |
12.6 mph, 2021 |
5.9 mph, 2025 |
| Minimum Feels-like |
14.9 °C |
23:44 |
14.9 °C |
18.6 °C, 2023 |
4.5 °C, 2018 |
| Maximum Feels-like |
22.2 °C |
12:55 |
22.2 °C |
30.2 °C, 2011 |
15.1 °C, 2018 |
| Mean Feels-like |
18.7 °C |
|
18.7 °C |
23.2 °C, 2023 |
10.3 °C, 2018 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
1 |
06:15 |
1 |
1, 2026 |
0, 2021 |
| Maximum PM2.5 |
8 |
22:30 |
8 |
8, 2026 |
8, 2026 |
| Mean PM2.5 |
3 |
|
3 |
3, 2026 |
3, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
7.0 °C (+0.3) |
7.0 °C (+0.3) |
14.8 °C (+8.1), 2011 |
1.9 °C (-4.8), 2024 |
| Humidity Range |
40% |
40% |
54%, 2011 |
11%, 2024 |
| Pressure Range |
14 hPa |
14 hPa |
16 hPa, 2022 |
2 hPa, 2011 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
8.5 [81%] | 8.5 hrs (204%) [81%] |
10.3 [98%], 2011 |
0 [0%], 2010 |
| Wet Hours |
1 [Mean rain rate: 0.8 mm/h] | 1 hrs (63%) [4.2%] |
9, 2010 |
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 |
17.0 °C |