| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
6.7 °C (+2.7) |
23:58 |
6.8 °C (+2.8) |
11.9 °C (+7.9), 2015 |
-2.9 °C (-6.9), 2023 |
| Maximum Temperature |
11.1 °C (+1.8) |
13:39 |
11.4 °C (+2.2) |
14.8 °C (+5.6), 2018 |
-0.7 °C (-9.9), 2010 |
| Mean Temperature |
8.9 °C (+2.2) |
|
9.5 °C (+2.5) |
13.4 °C, 2018 |
-1.3 °C, 2010 |
| Minimum Humidity |
78% |
13:56 |
80% |
93%, 2023 |
61%, 2012 |
| Maximum Humidity |
91% |
02:42 |
92% |
98%, 2009 |
82%, 2015 |
| Mean Humidity |
87% |
|
88% |
95%, 2009 |
74%, 2015 |
| Minimum Pressure |
998 hPa |
00:03 |
998 hPa |
1030 hPa, 2013 |
993 hPa, 2009 |
| Maximum Pressure |
1007 hPa |
22:47 |
1010 hPa |
1035 hPa, 2013 |
999 hPa, 2018 |
| Mean Pressure |
1003 hPa |
|
1003 hPa |
1033 hPa, 2013 |
998 hPa, 2018 |
| Mean Wind Speed |
4.5 mph (-0.6) |
|
7.9 mph (+2.8) |
8.1 mph, 2015 |
0.7 mph, 2016 |
| Maximum Wind Speed |
12.2 mph |
13:16 |
16.6 mph |
18.5 mph, 2014 |
5.5 mph, 2016 |
| Maximum Gust |
19.6 mph |
00:47 |
27.7 mph |
30.6 mph, 2014 |
8.1 mph, 2013 |
| Mean Wind Direction |
SW |
|
|
|
|
| Rainfall |
5.2 mm |
|
9.4 mm (256%) |
10.9 mm, 2009 |
|
| Maximum Hourly Rain |
3.4 mm |
19:18 |
|
4.4 mm, 2009 |
|
| Maximum 10-min Rain |
2.2 mm |
18:56 |
|
2.2 mm, 2025 |
|
| Maximum Rain Rate |
24 mm/h |
18:51 |
|
24 mm/h, 2025 |
|
| Minimum Dew Point |
5.2 °C |
23:47 |
4.7 °C |
10.3 °C, 2018 |
-5.4 °C, 2010 |
| Maximum Dew Point |
8.5 °C |
00:17 |
9.2 °C |
12.3 °C, 2018 |
-2.7 °C, 2010 |
| Mean Dew Point |
6.9 °C |
|
7.6 °C |
11.7 °C, 2018 |
-3.5 °C, 2010 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 7.6 °C * |
08:45 |
6.8 °C |
11.9 °C, 2015 |
-1.8 °C, 2010 |
| Day Maximum (09-21) |
11.1 °C |
13:39 |
11.4 °C |
14.8 °C, 2018 |
-0.7 °C, 2010 |
| Max 10m Temp Rise |
0.5 °C |
11:23 |
0.4 °C |
0.5 °C, 2009 |
0.2 °C, 2010 |
| Max 1hr Temp Rise |
1.4 °C |
11:27 |
1.2 °C |
1.5 °C, 2011 |
0.5 °C, 2010 |
| Max 1hr Hum Rise |
5% |
14:55 |
5% |
9%, 2017 |
2%, 2022 |
| Max 10m Temp Fall |
0.4 °C |
15:25 |
0.4 °C |
0.7 °C, 2009 |
0.1 °C, 2015 |
| Max 1hr Temp Fall |
1.3 °C |
23:52 |
1.2 °C |
1.8 °C, 2012 |
0.4 °C, 2015 |
| Max 1hr Hum Fall |
4% |
11:36 |
4% |
14%, 2012 |
1%, 2023 |
| Max 10m Wind Speed |
9.1 mph |
11:23 |
12.4 mph |
14.0 mph, 2014 |
3.7 mph, 2013 |
| Minimum Feels-like |
4.6 °C |
09:12 |
3.8 °C |
12.8 °C, 2018 |
-8.7 °C, 2010 |
| Maximum Feels-like |
11.3 °C |
13:39 |
12.1 °C |
17.0 °C, 2018 |
-1.7 °C, 2010 |
| Mean Feels-like |
7.5 °C |
|
8.5 °C |
15.6 °C, 2018 |
-5.8 °C, 2010 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
24 hrs, 2010 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
4.4 °C (-0.8) |
4.6 °C (-0.6) |
6.1 °C (+0.9), 2024 |
1.1 °C (-4.1), 2010 |
| Humidity Range |
13% |
11% |
26%, 2012 |
3%, 2023 |
| Pressure Range |
9 hPa |
12 hPa |
17 hPa, 2020 |
1 hPa, 2015 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
5.6 [77%] | 5.6 hrs (130%) [38%] |
7.4 [102%], 2021 |
0 [0%], 2010 |
| Wet Hours |
4 [Mean rain rate: 1.3 mm/h] | 11 hrs (275%) [23%] |
7, 2009 |
0, 2012 |
| 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 |
8.4 °C |