| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
6.5 °C (-1.2) |
05:16 |
5.3 °C (-2.3) |
12.6 °C (+4.9), 2023 |
2.5 °C (-5.2), 2010 |
| Maximum Temperature |
20.4 °C (+3.8) |
15:24 |
17.6 °C (+1.1) |
22.2 °C (+5.6), 2018 |
9.8 °C (-6.8), 2012 |
| Mean Temperature |
14.3 °C (+1.3) |
|
12.1 °C (-0.6) |
15.6 °C, 2023 |
7.1 °C, 2021 |
| Minimum Humidity |
28% |
15:07 |
36% |
60%, 2022 |
28%, 2016 |
| Maximum Humidity |
67% |
07:01 |
80% |
98%, 2024 |
67%, 2016 |
| Mean Humidity |
41% |
|
56% |
78%, 2024 |
41%, 2016 |
| Minimum Pressure |
1015 hPa |
23:10 |
1020 hPa |
1025 hPa, 2018 |
988 hPa, 2015 |
| Maximum Pressure |
1024 hPa |
00:45 |
1027 hPa |
1028 hPa, 2019 |
1002 hPa, 2015 |
| Mean Pressure |
1019 hPa |
|
1023 hPa |
1026 hPa, 2018 |
994 hPa, 2015 |
| Mean Wind Speed |
3.0 mph (-1.7) |
|
4.3 mph (-0.4) |
11.6 mph, 2015 |
2.4 mph, 2010 |
| Maximum Wind Speed |
9.9 mph |
18:00 |
12.5 mph |
25.5 mph, 2015 |
7.5 mph, 2010 |
| Maximum Gust |
16.8 mph |
18:48 |
18.5 mph |
42.0 mph, 2015 |
10.6 mph, 2010 |
| Mean Wind Direction |
SSE |
|
|
|
|
| Rainfall |
0.0 mm |
|
0.2 mm (3%) |
4.3 mm, 2021 |
|
| Maximum Hourly Rain |
n/a |
|
|
3.4, 2021 |
|
| Maximum 10-min Rain |
n/a |
|
|
1.5, 2021 |
|
| Maximum Rain Rate |
n/a |
|
|
10.8, 2015 |
|
| Minimum Dew Point |
-3.7 °C |
00:11 |
-1.2 °C |
10.3 °C, 2023 |
-3.7 °C, 2016 |
| Maximum Dew Point |
5.4 °C |
08:10 |
6.6 °C |
13.9 °C, 2015 |
3.6 °C, 2019 |
| Mean Dew Point |
0.7 °C |
|
2.6 °C |
11.5 °C, 2023 |
0.7 °C, 2016 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
6.5 °C |
05:16 |
5.5 °C |
12.6 °C, 2023 |
2.5 °C, 2010 |
| Day Maximum (09-21) |
20.4 °C |
15:24 |
17.6 °C |
22.2 °C, 2018 |
9.8 °C, 2012 |
| Max 10m Temp Rise |
0.9 °C |
07:26 |
0.8 °C |
1.3 °C, 2018 |
0.3 °C, 2012 |
| Max 1hr Temp Rise |
4.5 °C |
08:12 |
3.6 °C |
4.8 °C, 2018 |
1.2 °C, 2012 |
| Max 1hr Hum Rise |
9% |
02:22 |
8% |
23%, 2021 |
4%, 2011 |
| Max 10m Temp Fall |
0.5 °C |
18:30 |
0.6 °C |
0.8 °C, 2021 |
0.3 °C, 2010 |
| Max 1hr Temp Fall |
1.9 °C |
19:08 |
2.0 °C |
3.3 °C, 2021 |
1.0 °C, 2012 |
| Max 1hr Hum Fall |
15% |
08:38 |
15% |
22%, 2018 |
7%, 2013 |
| Max 10m Wind Speed |
7.8 mph |
18:01 |
9.6 mph |
18.9 mph, 2015 |
5.8 mph, 2019 |
| Minimum Feels-like |
6.5 °C |
04:45 |
4.3 °C |
14.1 °C, 2023 |
-1.3 °C, 2019 |
| Maximum Feels-like |
20.4 °C |
15:21 |
17.7 °C |
22.8 °C, 2018 |
9.3 °C, 2012 |
| Mean Feels-like |
14.3 °C |
|
12.0 °C |
17.6 °C, 2023 |
4.9 °C, 2012 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
13.9 °C (+5.0) |
12.3 °C (+3.3) |
15.1 °C (+6.2), 2018 |
4.1 °C (-4.8), 2015 |
| Humidity Range |
39% |
44% |
56%, 2018 |
28%, 2013 |
| Pressure Range |
9 hPa |
7 hPa |
14 hPa, 2015 |
2 hPa, 2023 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
13 [95%] | 48 hrs (165%) [71%] |
13.7 [100%], 2018 |
0.1 [1%], 2012 |
| Wet Hours |
0 | 1 hrs (16%) [0.8%] |
2, 2012 |
0, 2010 |
| Cloud Cover |
am: Sunny pm: Sunny transitioned to Hazy |
| Events |
Maximum possible sunshine |
| Comments |
- |
| Extra Comments |
|
| Issues |
Wind data from Harpenden |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
0.0 °C |