| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
3.0 °C (+0.0) |
04:42 |
0.7 °C (-2.3) |
10.3 °C (+7.3), 2017 |
-3.1 °C (-6.1), 2009 |
| Maximum Temperature |
10.0 °C (+2.1) |
21:48 |
8.4 °C (+0.5) |
13.0 °C (+5.1), 2020 |
0.2 °C (-7.7), 2009 |
| Mean Temperature |
6.6 °C (+1.1) |
|
5.0 °C (-0.9) |
10.9 °C, 2017 |
-1.4 °C, 2009 |
| Minimum Humidity |
82% |
14:05 |
81% |
87%, 2009 |
41%, 2012 |
| Maximum Humidity |
98% |
08:30 |
96% |
98%, 2011 |
65%, 2012 |
| Mean Humidity |
93% |
|
90% |
93%, 2010 |
54%, 2012 |
| Minimum Pressure |
1020 hPa |
20:14 |
1022 hPa |
1035 hPa, 2012 |
991 hPa, 2009 |
| Maximum Pressure |
1028 hPa |
02:14 |
1028 hPa |
1038 hPa, 2012 |
1001 hPa, 2021 |
| Mean Pressure |
1024 hPa |
|
1025 hPa |
1036 hPa, 2012 |
996 hPa, 2021 |
| Mean Wind Speed |
6.9 mph (+1.8) |
|
6.2 mph (+1.1) |
10.1 mph, 2024 |
2.5 mph, 2025 |
| Maximum Wind Speed |
16.1 mph |
|
14.2 mph |
21.5 mph, 2016 |
8.7 mph, 2015 |
| Maximum Gust |
20.8 mph |
12:32 |
19.1 mph |
33.4 mph, 2020 |
10.9 mph, 2015 |
| Mean Wind Direction |
SW |
|
|
|
|
| Rainfall |
trace |
|
0.2 mm (6%) |
10, 2009 |
|
| Maximum Hourly Rain |
n/a |
|
|
2.9, 2021 |
|
| Maximum 10-min Rain |
n/a |
|
|
0.8, 2021 |
|
| Maximum Rain Rate |
n/a |
|
|
18, 2020 |
|
| Minimum Dew Point |
2.6 °C |
04:42 |
-1.1 °C |
6.9 °C, 2017 |
-11.5 °C, 2012 |
| Maximum Dew Point |
8.8 °C |
21:32 |
7.2 °C |
10.3 °C, 2020 |
-7.9 °C, 2012 |
| Mean Dew Point |
5.5 °C |
|
3.5 °C |
7.8 °C, 2017 |
-9.7 °C, 2012 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
3.0 °C |
04:40 |
0.7 °C |
10.3 °C, 2017 |
-3.1 °C, 2009 |
| Day Maximum (09-21) |
10.0 °C |
21:00 |
8.4 °C |
13.0 °C, 2020 |
0.2 °C, 2009 |
| Max 10m Temp Rise |
0.4 °C |
10:53 |
0.3 °C |
0.9 °C, 2025 |
0.2 °C, 2016 |
| Max 1hr Temp Rise |
1.7 °C |
11:31 |
1.4 °C |
3.0 °C, 2025 |
0.7 °C, 2016 |
| Max 1hr Hum Rise |
4% |
16:35 |
4% |
8%, 2012 |
3%, 2019 |
| Max 10m Temp Fall |
0.2 °C |
22:55 |
0.2 °C |
0.5 °C, 2010 |
0.2 °C, 2011 |
| Max 1hr Temp Fall |
0.9 °C |
01:45 |
0.8 °C |
1.8 °C, 2010 |
0.6 °C, 2015 |
| Max 1hr Hum Fall |
8% |
12:33 |
5% |
13%, 2016 |
3%, 2017 |
| Max 10m Wind Speed |
10.9 mph |
12:42 |
9.9 mph |
16.0 mph, 2016 |
6.1 mph, 2015 |
| Minimum Feels-like |
-1.2 °C |
08:40 |
-4.6 °C |
10.3 °C, 2017 |
-8.7 °C, 2012 |
| Maximum Feels-like |
10.7 °C |
20:56 |
8.8 °C |
14.0 °C, 2024 |
-1.8 °C, 2012 |
| Mean Feels-like |
4.3 °C |
|
2.6 °C |
11.3 °C, 2017 |
-5.6 °C, 2012 |
| Air-frost Hrs |
0 hrs |
|
3 hrs |
18 hrs, 2012 |
0 hrs, 2010 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
7.0 °C (+2.1) |
7.8 °C (+2.9) |
9.1 °C (+4.2), 2025 |
1.3 °C (-3.6), 2017 |
| Humidity Range |
16% |
16% |
33%, 2013 |
7%, 2017 |
| Pressure Range |
8 hPa |
6 hPa |
22 hPa, 2013 |
2 hPa, 2015 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0.1 [1%] | 0.3 hrs (6%) [1.8%] |
8.3 [101%], 2025 |
0 [0%], 2009 |
| Wet Hours |
0.3 | 0.8 hrs (22%) [1.7%] |
6, 2020 |
, 2009 |
| Cloud Cover |
am: Overcast transitioned to Mostly Cloudy pm: Overcast |
| Events |
None |
| Comments |
possible 20-22 broken Light Showers |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
0.0 °C |