| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
12.8 °C (+6.0) |
22:12 |
10.3 °C (+3.5) |
13.6 °C (+6.8), 2010 |
1.3 °C (-5.5), 2021 |
| Maximum Temperature |
17.4 °C (+5.1) |
14:48 |
15.7 °C (+3.5) |
17.4 °C (+5.1), 2011 |
8.9 °C (-3.4), 2021 |
| Mean Temperature |
15.3 °C (+5.6) |
|
13.6 °C (+3.5) |
15.3 °C, 2011 |
5.8 °C, 2021 |
| Minimum Humidity |
78% |
15:03 |
72% |
90%, 2015 |
54%, 2013 |
| Maximum Humidity |
95% |
23:59 |
93% |
98%, 2009 |
80%, 2016 |
| Mean Humidity |
87% |
|
85% |
93%, 2022 |
71%, 2013 |
| Minimum Pressure |
991 hPa |
23:34 |
998 hPa |
1028 hPa, 2024 |
978 hPa, 2023 |
| Maximum Pressure |
996 hPa |
00:12 |
1007 hPa |
1031 hPa, 2024 |
985 hPa, 2019 |
| Mean Pressure |
994 hPa |
|
1002 hPa |
1029 hPa, 2024 |
982 hPa, 2019 |
| Mean Wind Speed |
4.9 mph (+0.3) |
|
4.7 mph (+0.1) |
8.1 mph, 2025 |
1.7 mph, 2017 |
| Maximum Wind Speed |
13.8 mph |
|
12.3 mph |
20.4 mph, 2013 |
6.9 mph, 2015 |
| Maximum Gust |
20.1 mph |
11:13 |
17.6 mph |
31.1 mph, 2025 |
9.0 mph, 2015 |
| Mean Wind Direction |
SSE |
|
|
|
|
| Rainfall |
6.6 mm |
|
8.0 mm (119%) |
24.0 mm, 2022 |
|
| Maximum Hourly Rain |
5.0 mm |
17:10 |
|
8.4 mm, 2022 |
|
| Maximum 10-min Rain |
1.6 mm |
16:45 |
|
3.4 mm, 2022 |
|
| Maximum Rain Rate |
15 mm/h |
16:36 |
|
42 mm/h, 2022 |
|
| Minimum Dew Point |
11.5 °C |
21:48 |
8.7 °C |
11.5 °C, 2011 |
-1.8 °C, 2016 |
| Maximum Dew Point |
14.3 °C |
10:52 |
13.3 °C |
14.3 °C, 2011 |
4.9 °C, 2016 |
| Mean Dew Point |
13.1 °C |
|
11.0 °C |
13.1 °C, 2011 |
1.9 °C, 2016 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 14.2 °C * |
21:00 |
11.6 °C |
14.2 °C, 2011 |
1.3 °C, 2021 |
| Day Maximum (09-21) |
17.4 °C |
14:47 |
15.6 °C |
17.4 °C, 2011 |
8.9 °C, 2021 |
| Max 10m Temp Rise |
0.2 °C |
01:05 |
0.3 °C |
0.6 °C, 2009 |
0.1 °C, 2014 |
| Max 1hr Temp Rise |
0.7 °C |
11:02 |
0.9 °C |
2.3 °C, 2016 |
0.3 °C, 2014 |
| Max 1hr Hum Rise |
5% |
16:36 |
4% |
11%, 2023 |
1%, 2015 |
| Max 10m Temp Fall |
0.2 °C |
17:01 |
0.2 °C |
0.8 °C, 2009 |
0.2 °C, 2010 |
| Max 1hr Temp Fall |
0.6 °C |
17:28 |
0.7 °C |
2.3 °C, 2009 |
0.4 °C, 2024 |
| Max 1hr Hum Fall |
8% |
11:05 |
8% |
16%, 2009 |
1%, 2015 |
| Max 10m Wind Speed |
10.2 mph |
11:15 |
8.4 mph |
14.5 mph, 2013 |
0.9 mph, 2020 |
| Minimum Feels-like |
14.8 °C |
21:44 |
10.4 °C |
14.8 °C, 2011 |
-0.5 °C, 2016 |
| Maximum Feels-like |
20.5 °C |
14:34 |
18.5 °C |
20.5 °C, 2011 |
8.4 °C, 2012 |
| Mean Feels-like |
18.2 °C |
|
15.4 °C |
18.2 °C, 2011 |
4.5 °C, 2012 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
4.6 °C (-0.9) |
5.4 °C (-0.1) |
9.0 °C (+3.5), 2016 |
1.7 °C (-3.8), 2024 |
| Humidity Range |
17% |
21% |
42%, 2013 |
5%, 2015 |
| Pressure Range |
5 hPa |
9 hPa |
18 hPa, 2013 |
2 hPa, 2025 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0.1 [1%] | 7.6 hrs (84%) [30%] |
6 [70%], 2013 |
0 [0%], 2015 |
| Wet Hours |
3
[Mean rain rate: 2.2 mm/h] | 4 hrs (63%) [5.6%] |
7, 2022 |
0, 2010 |
| Cloud Cover |
Overcast |
| Events |
None |
| Comments |
08 Moderate Shower; 1630-1730 Moderate/Heavy Rain; 23- Slight Rain |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
0.0 °C |
