| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
1.8 °C (-4.7) |
06:27 |
5.3 °C (-1.3) |
14.7 °C (+8.2), 2025 |
0.8 °C (-5.7), 2021 |
| Maximum Temperature |
9.2 °C (-2.5) |
15:12 |
12.7 °C (+0.8) |
17.2 °C (+5.5), 2025 |
8.5 °C (-3.2), 2012 |
| Mean Temperature |
4.8 °C (-3.6) |
|
9.2 °C (-0.3) |
15.8 °C, 2025 |
4.8 °C, 2020 |
| Minimum Humidity |
81% |
15:03 |
72% |
90%, 2011 |
60%, 2016 |
| Maximum Humidity |
97% |
09:44 |
93% |
98%, 2011 |
79%, 2016 |
| Mean Humidity |
92% |
|
85% |
94%, 2011 |
72%, 2016 |
| Minimum Pressure |
1036 hPa |
23:49 |
1015 hPa |
1036 hPa, 2020 |
967 hPa, 2023 |
| Maximum Pressure |
1042 hPa |
09:31 |
1028 hPa |
1042 hPa, 2020 |
994 hPa, 2023 |
| Mean Pressure |
1039 hPa |
|
1021 hPa |
1039 hPa, 2020 |
982 hPa, 2023 |
| Mean Wind Speed |
0.2 mph (-4.4) |
|
4.3 mph (-0.3) |
7.7 mph, 2016 |
0.2 mph, 2020 |
| Maximum Wind Speed |
3.0 mph |
11:24 |
10.8 mph |
20.8 mph, 2016 |
3.0 mph, 2020 |
| Maximum Gust |
6.0 mph |
11:25 |
22.3 mph |
35.5 mph, 2016 |
6.0 mph, 2020 |
| Mean Wind Direction |
NW |
|
|
|
|
| Rainfall |
0.0 mm |
|
4.0 mm (36%) |
8.5 mm, 2013 |
|
| Maximum Hourly Rain |
n/a |
|
|
3.7, 2013 |
|
| Maximum 10-min Rain |
n/a |
|
|
1.1, 2010 |
|
| Maximum Rain Rate |
n/a |
|
|
20, 2010 |
|
| Minimum Dew Point |
0.9 °C |
06:27 |
3.2 °C |
12.4 °C, 2015 |
-2.2 °C, 2016 |
| Maximum Dew Point |
6.7 °C |
13:17 |
10.0 °C |
14.6 °C, 2010 |
4.5 °C, 2016 |
| Mean Dew Point |
3.7 °C |
|
6.7 °C |
13.2 °C, 2015 |
1.0 °C, 2016 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
1.8 °C |
06:28 |
7.3 °C |
15.2 °C, 2010 |
0.8 °C, 2021 |
| Day Maximum (09-21) |
9.2 °C |
15:13 |
12.7 °C |
17.2 °C, 2025 |
8.5 °C, 2012 |
| Max 10m Temp Rise |
0.5 °C |
11:35 |
0.5 °C |
0.6 °C, 2009 |
0.2 °C, 2010 |
| Max 1hr Temp Rise |
1.7 °C |
11:35 |
1.6 °C |
2.0 °C, 2017 |
0.6 °C, 2010 |
| Max 1hr Hum Rise |
4% |
17:34 |
7% |
9%, 2010 |
2%, 2015 |
| Max 10m Temp Fall |
0.4 °C |
16:23 |
0.7 °C |
1.2 °C, 2010 |
0.1 °C, 2022 |
| Max 1hr Temp Fall |
1.7 °C |
17:12 |
1.9 °C |
4.5 °C, 2010 |
0.1 °C, 2022 |
| Max 1hr Hum Fall |
6% |
13:51 |
8% |
19%, 2013 |
1%, 2022 |
| Max 10m Wind Speed |
0.0 mph |
11:25 |
4.8 mph |
16.2 mph, 2016 |
0.0 mph, 2020 |
| Minimum Feels-like |
1.8 °C |
06:25 |
4.6 °C |
16.3 °C, 2025 |
-2.3 °C, 2016 |
| Maximum Feels-like |
9.2 °C |
14:41 |
14.2 °C |
19.9 °C, 2010 |
6.7 °C, 2016 |
| Mean Feels-like |
4.8 °C |
|
10.0 °C |
17.7 °C, 2010 |
2.4 °C, 2016 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
7.4 °C (+2.2) |
7.3 °C (+2.0) |
8.6 °C (+3.4), 2021 |
1.8 °C (-3.4), 2015 |
| Humidity Range |
16% |
21% |
32%, 2013 |
4%, 2015 |
| Pressure Range |
5 hPa |
13 hPa |
27 hPa, 2023 |
3 hPa, 2016 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
5 [60%] | 20 hrs (132%) [47%] |
7 [84%], 2021 |
0 [0%], 2015 |
| Wet Hours |
0 | 5.5 hrs (52%) [4.6%] |
6, 2015 |
0, 2012 |
| Cloud Cover |
am: Overcast transitioned to Partly Cloudy pm: Mostly Sunny |
| Events |
Dense Fog |
| Comments |
v dense fog til 10 |
| Extra Comments |
|
| Issues |
wind sensor not reporting properly - v low speeds |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
10.5 °C |