Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
Minimum Temperature |
5.8 °C (-0.6) |
22:59 |
5.8 °C (-0.1) |
12.1 °C (+5.7), 2018 |
2.3 °C (-4.1), 2010 |
Maximum Temperature |
11.0 °C (-4.1) |
14:32 |
13.7 °C (-0.4) |
25.6 °C (+10.6), 2011 |
9.4 °C (-5.7), 2024 |
Mean Temperature |
8.4 °C (-2.3) |
|
9.7 °C (-0.2) |
18.0 °C, 2011 |
7.0 °C, 2024 |
Minimum Humidity |
60% |
04:36 |
47% |
67%, 2024 |
29%, 2019 |
Maximum Humidity |
90% |
22:18 |
86% |
97%, 2023 |
75%, 2011 |
Mean Humidity |
74% |
|
67% |
82%, 2014 |
50%, 2011 |
Minimum Pressure |
1019 hPa |
17:07 |
1009 hPa |
1027 hPa, 2024 |
1002 hPa, 2019 |
Maximum Pressure |
1023 hPa |
01:15 |
1014 hPa |
1033 hPa, 2015 |
1004 hPa, 2012 |
Mean Pressure |
1021 hPa |
|
1011 hPa |
1030 hPa, 2015 |
1004 hPa, 2012 |
Mean Wind Speed |
4.1 mph (-0.8) |
|
3.7 mph (-1.2) |
7.1 mph, 2022 |
2.7 mph, 2011 |
Maximum Wind Speed |
8.6 mph |
03:33 |
11.1 mph |
18.5 mph, 2012 |
7.7 mph, 2024 |
Maximum Gust |
12.6 mph |
03:43 |
17.4 mph |
25.1 mph, 2012 |
11.5 mph, 2017 |
Mean Wind Direction |
WNW |
|
|
|
|
Rainfall |
5.5 mm |
|
44.9 mm (146%) |
5.5 mm, 2016 |
|
Maximum Hourly Rain |
1.3 mm |
19:02 |
|
2.6 mm, 2018 |
|
Maximum 10-min Rain |
0.4 mm |
17:08 |
|
1.3 mm, 2018 |
|
Maximum Rain Rate |
1.8 mm/h |
17:08 |
|
13 mm/h, 2018 |
|
Minimum Dew Point |
0.6 °C |
04:49 |
0.8 °C |
6.7 °C, 2014 |
-3.6 °C, 2010 |
Maximum Dew Point |
6.3 °C |
17:46 |
6.9 °C |
14.6 °C, 2018 |
2.4 °C, 2010 |
Mean Dew Point |
3.9 °C |
|
3.6 °C |
11.8 °C, 2018 |
0.2 °C, 2010 |
Measure | Value | Time |
Month cumul. | Record High | Record Low |
Night Minimum (21-09) |
* 7.4 °C * |
06:13 |
6.2 °C |
13.2 °C, 2018 |
2.3 °C, 2010 |
Day Maximum (09-21) |
11.0 °C |
14:32 |
13.7 °C |
25.6 °C, 2011 |
9.4 °C, 2024 |
Max 10m Temp Rise |
0.2 °C |
08:54 |
0.6 °C |
1.1 °C, 2025 |
0.2 °C, 2016 |
Max 1hr Temp Rise |
0.9 °C |
09:28 |
2.3 °C |
3.6 °C, 2019 |
0.9 °C, 2016 |
Max 1hr Hum Rise |
8% |
16:15 |
10% |
28%, 2012 |
5%, 2024 |
Max 10m Temp Fall |
0.3 °C |
15:38 |
0.6 °C |
1.1 °C, 2012 |
0.3 °C, 2013 |
Max 1hr Temp Fall |
1.1 °C |
16:10 |
1.7 °C |
4.3 °C, 2012 |
0.9 °C, 2024 |
Max 1hr Hum Fall |
3% |
03:40 |
15% |
17%, 2014 |
3%, 2016 |
Max 10m Wind Speed |
6.5 mph |
03:52 |
8.3 mph |
13.6 mph, 2018 |
5.8 mph, 2024 |
Minimum Feels-like |
4.2 °C |
22:32 |
3.6 °C |
12.1 °C, 2018 |
-0.4 °C, 2021 |
Maximum Feels-like |
11.0 °C |
14:14 |
13.8 °C |
25.8 °C, 2018 |
9.4 °C, 2024 |
Mean Feels-like |
7.1 °C |
|
8.9 °C |
20.1 °C, 2018 |
5.5 °C, 2024 |
Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
Temperature Range |
5.2 °C (-3.5) |
7.9 °C (-0.4) |
16.4 °C (+7.7), 2019 |
5.2 °C (-3.5), 2016 |
Humidity Range |
30% |
39% |
50%, 2012 |
24%, 2024 |
Pressure Range |
4 hPa |
5 hPa |
13 hPa, 2019 |
1 hPa, 2012 |
Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
Sun Hours |
0 [0%] | 101 hrs (87%) [37%] |
13 [100%], 2020 |
0 [0%], 2016 |
Wet Hours |
10 [Mean rain rate: 0.6 mm/h] | 51 hrs (151%) [9.7%] |
10, 2016 |
0, 2009 |
Cloud Cover |
Overcast |
Events |
None |
Comments |
14- Rain |
Extra Comments |
|
Issues |
Wind data from Harpenden (accidentally cut off from 08) |
Observer Absent? |
Yes - observations may be unreliable |
Pond Temperature @ Hampstead Heath |
0.0 °C |