| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
-1.7 °C (-4.7) |
02:15 |
-1.7 °C (-4.7) |
9.5 °C (+6.5), 2016 |
-2.5 °C (-5.5), 2009 |
| Maximum Temperature |
6.9 °C (-1.0) |
16:49 |
6.9 °C (-1.0) |
13.9 °C (+6.0), 2016 |
1.9 °C (-6.0), 2019 |
| Mean Temperature |
3.5 °C (-2.8) |
|
3.5 °C (-2.8) |
12.2 °C, 2016 |
0.1 °C, 2009 |
| Minimum Humidity |
80% |
00:00 |
80% |
88%, 2019 |
43%, 2012 |
| Maximum Humidity |
95% |
23:59 |
95% |
98%, 2014 |
79%, 2012 |
| Mean Humidity |
86% |
|
86% |
93%, 2019 |
64%, 2009 |
| Minimum Pressure |
1024 hPa |
10:14 |
1024 hPa |
1029 hPa, 2012 |
982 hPa, 2014 |
| Maximum Pressure |
1028 hPa |
22:14 |
1028 hPa |
1036 hPa, 2024 |
996 hPa, 2014 |
| Mean Pressure |
1026 hPa |
|
1026 hPa |
1034 hPa, 2024 |
989 hPa, 2019 |
| Mean Wind Speed |
5.4 mph (+0.3) |
|
5.4 mph (+0.3) |
12.3 mph, 2016 |
1.6 mph, 2021 |
| Maximum Wind Speed |
12.3 mph |
|
12.3 mph |
25.3 mph, 2016 |
7.5 mph, 2021 |
| Maximum Gust |
17.3 mph |
01:58 |
17.3 mph |
38.0 mph, 2020 |
11.4 mph, 2021 |
| Mean Wind Direction |
WSW |
|
|
|
|
| Rainfall |
trace |
|
0.1 mm (6%) |
13.2, 2019 |
|
| Maximum Hourly Rain |
n/a |
|
|
3.7, 2014 |
|
| Maximum 10-min Rain |
n/a |
|
|
2.4, 2014 |
|
| Maximum Rain Rate |
n/a |
|
|
48, 2014 |
|
| Minimum Dew Point |
-4.7 °C |
02:10 |
-4.7 °C |
6.5 °C, 2017 |
-9.5 °C, 2009 |
| Maximum Dew Point |
5.5 °C |
16:34 |
5.5 °C |
10.0 °C, 2016 |
-3.0 °C, 2012 |
| Mean Dew Point |
1.5 °C |
|
1.5 °C |
8.2 °C, 2017 |
-6.0 °C, 2012 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
-1.7 °C |
02:15 |
-1.7 °C |
11.6 °C, 2016 |
-1.7 °C, 2011 |
| Day Maximum (09-21) |
6.9 °C |
16:45 |
6.9 °C |
13.9 °C, 2016 |
1.9 °C, 2019 |
| Max 10m Temp Rise |
0.3 °C |
10:38 |
0.3 °C |
0.4 °C, 2022 |
0.2 °C, 2016 |
| Max 1hr Temp Rise |
1.2 °C |
10:47 |
1.2 °C |
1.8 °C, 2022 |
0.4 °C, 2025 |
| Max 1hr Hum Rise |
5% |
13:13 |
5% |
20%, 2015 |
1%, 2017 |
| Max 10m Temp Fall |
0.2 °C |
01:51 |
0.2 °C |
1.0 °C, 2018 |
0.1 °C, 2017 |
| Max 1hr Temp Fall |
0.7 °C |
01:51 |
0.7 °C |
2.2 °C, 2014 |
0.4 °C, 2017 |
| Max 1hr Hum Fall |
2% |
09:41 |
2% |
15%, 2012 |
1%, 2017 |
| Max 10m Wind Speed |
9.0 mph |
00:06 |
9.0 mph |
18.8 mph, 2016 |
5.7 mph, 2021 |
| Minimum Feels-like |
-8.0 °C |
01:59 |
-8.0 °C |
6.3 °C, 2017 |
-8.0 °C, 2011 |
| Maximum Feels-like |
6.9 °C |
16:38 |
6.9 °C |
14.7 °C, 2016 |
-0.5 °C, 2012 |
| Mean Feels-like |
0.9 °C |
|
0.9 °C |
12.6 °C, 2016 |
-4.5 °C, 2012 |
| Air-frost Hrs |
5 hrs |
|
5 hrs |
10 hrs, 2012 |
0 hrs, 2013 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
8.6 °C (+3.7) |
8.6 °C (+3.7) |
8.6 °C (+3.7), 2011 |
1.4 °C (-3.5), 2021 |
| Humidity Range |
15% |
15% |
41%, 2014 |
4%, 2017 |
| Pressure Range |
4 hPa |
4 hPa |
14 hPa, 2013 |
2 hPa, 2016 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0.2 [2%] | 0.2 hrs (8%) [2.4%] |
8 [98%], 2024 |
0 [0%], 2017 |
| Wet Hours |
0.5 | 0.5 hrs (27%) [2.1%] |
20, 2019 |
, 2009 |
| Cloud Cover |
am: Mostly Cloudy transitioned to Overcast pm: Overcast |
| Events |
Air Frost |
| Comments |
Air frost; 1030, 1230 Light/Moderate Showers |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
0.0 °C |