| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
8.5 °C (-0.8) |
00:05 |
8.4 °C (-1.2) |
15.3 °C (+6.0), 2010 |
6.0 °C (-3.3), 2009 |
| Maximum Temperature |
11.8 °C (-4.0) |
16:17 |
14.5 °C (-1.6) |
23.9 °C (+8.1), 2023 |
11.8 °C (-4.0), 2012 |
| Mean Temperature |
10.9 °C (-2.4) |
|
11.7 °C (-1.4) |
18.4 °C, 2023 |
9.9 °C, 2009 |
| Minimum Humidity |
88% |
08:54 |
68% |
88%, 2012 |
56%, 2009 |
| Maximum Humidity |
98% |
21:01 |
96% |
98%, 2012 |
81%, 2016 |
| Mean Humidity |
95% |
|
85% |
95%, 2012 |
75%, 2016 |
| Minimum Pressure |
1011 hPa |
18:00 |
1007 hPa |
1029 hPa, 2021 |
990 hPa, 2024 |
| Maximum Pressure |
1022 hPa |
00:20 |
1015 hPa |
1032 hPa, 2021 |
995 hPa, 2024 |
| Mean Pressure |
1015 hPa |
|
1012 hPa |
1030 hPa, 2021 |
994 hPa, 2024 |
| Mean Wind Speed |
3.0 mph (-1.1) |
|
4.2 mph (+0.1) |
6.0 mph, 2019 |
0.7 mph, 2021 |
| Maximum Wind Speed |
6.7 mph |
17:50 |
11.7 mph |
18.1 mph, 2020 |
6.5 mph, 2021 |
| Maximum Gust |
9.8 mph |
17:48 |
17.2 mph |
28.9 mph, 2014 |
9.1 mph, 2021 |
| Mean Wind Direction |
E |
|
|
|
|
| Rainfall |
3.8 mm |
|
48.3 mm (288%) |
9.2 mm, 2024 |
|
| Maximum Hourly Rain |
2.0 mm |
11:44 |
|
4.6 mm, 2019 |
|
| Maximum 10-min Rain |
0.6 mm |
10:45 |
|
2.6 mm, 2019 |
|
| Maximum Rain Rate |
3.3 mm/h |
11:18 |
|
42 mm/h, 2024 |
|
| Minimum Dew Point |
7.4 °C |
11:59 |
6.8 °C |
13.0 °C, 2010 |
3.8 °C, 2009 |
| Maximum Dew Point |
11.4 °C |
18:12 |
11.8 °C |
17.1 °C, 2010 |
9.2 °C, 2009 |
| Mean Dew Point |
10.1 °C |
|
9.1 °C |
14.6 °C, 2010 |
6.4 °C, 2009 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
8.5 °C |
00:09 |
9.2 °C |
14.5 °C, 2010 |
6.0 °C, 2009 |
| Day Maximum (09-21) |
11.8 °C |
16:20 |
14.5 °C |
23.9 °C, 2023 |
11.8 °C, 2012 |
| Max 10m Temp Rise |
0.3 °C |
03:45 |
0.6 °C |
0.7 °C, 2015 |
0.2 °C, 2011 |
| Max 1hr Temp Rise |
0.7 °C |
04:30 |
2.0 °C |
2.9 °C, 2015 |
0.7 °C, 2012 |
| Max 1hr Hum Rise |
3% |
10:53 |
6% |
19%, 2019 |
3%, 2012 |
| Max 10m Temp Fall |
0.1 °C |
10:48 |
0.6 °C |
1.8 °C, 2019 |
0.1 °C, 2012 |
| Max 1hr Temp Fall |
0.2 °C |
23:58 |
1.8 °C |
3.6 °C, 2019 |
0.2 °C, 2012 |
| Max 1hr Hum Fall |
2% |
04:14 |
11% |
14%, 2014 |
2%, 2012 |
| Max 10m Wind Speed |
5.0 mph |
18:31 |
8.7 mph |
14.5 mph, 2014 |
3.8 mph, 2025 |
| Minimum Feels-like |
7.8 °C |
00:45 |
7.8 °C |
18.5 °C, 2010 |
4.7 °C, 2018 |
| Maximum Feels-like |
13.7 °C |
16:06 |
16.4 °C |
27.9 °C, 2023 |
13.7 °C, 2012 |
| Mean Feels-like |
12.2 °C |
|
12.6 °C |
21.9 °C, 2023 |
10.0 °C, 2009 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
3.3 °C (-3.1) |
6.2 °C (-0.3) |
10.1 °C (+3.7), 2023 |
3.3 °C (-3.1), 2012 |
| Humidity Range |
10% |
28% |
41%, 2009 |
10%, 2012 |
| Pressure Range |
11 hPa |
8 hPa |
12 hPa, 2020 |
2 hPa, 2010 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0 [0%] | 27 hrs (82%) [33%] |
10 [100%], 2022 |
0 [0%], 2012 |
| Wet Hours |
7
[Mean rain rate: 0.5 mm/h] | 40 hrs (312%) [21%] |
7, 2012 |
0, 2009 |
| Cloud Cover |
Overcast |
| Events |
None |
| Comments |
10-13 Light Rain, Drizzle at other times 09-23 |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
No |
| Pond Temperature @ Hampstead Heath |
0.0 °C |
