| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
15.5 °C (+1.6) |
23:56 |
15.8 °C (+1.4) |
18.4 °C (+4.5), 2018 |
8.6 °C (-5.3), 2014 |
| Maximum Temperature |
23.8 °C (+1.4) |
14:56 |
28.3 °C (+5.5) |
24.9 °C (+2.5), 2012 |
18.9 °C (-3.5), 2014 |
| Mean Temperature |
18.8 °C (+1.5) |
|
22.2 °C (+3.5) |
21.7 °C, 2018 |
13.8 °C, 2014 |
| Minimum Humidity |
43% |
16:11 |
36% |
72%, 2010 |
34%, 2013 |
| Maximum Humidity |
79% |
22:50 |
78% |
94%, 2020 |
79%, 2026 |
| Mean Humidity |
65% |
|
56% |
84%, 2015 |
56%, 2013 |
| Minimum Pressure |
1005 hPa |
06:01 |
1015 hPa |
1026 hPa, 2013 |
1000 hPa, 2020 |
| Maximum Pressure |
1011 hPa |
23:57 |
1020 hPa |
1028 hPa, 2013 |
1005 hPa, 2020 |
| Mean Pressure |
1007 hPa |
|
1018 hPa |
1027 hPa, 2013 |
1004 hPa, 2020 |
| Mean Wind Speed |
5.7 mph (+1.7) |
|
4.0 mph (-0.0) |
13.5 mph, 2016 |
2.0 mph, 2021 |
| Maximum Wind Speed |
17.4 mph |
15:21 |
12.5 mph |
26.4 mph, 2016 |
7.8 mph, 2013 |
| Maximum Gust |
26.5 mph |
15:22 |
19.0 mph |
45.2 mph, 2016 |
10.2 mph, 2013 |
| Mean Wind Direction |
WNW |
|
|
|
|
| Rainfall |
0.4 mm |
|
2.0 mm (6%) |
4.6 mm, 2011 |
|
| Maximum Hourly Rain |
0.4 mm |
18:37 |
|
3.6 mm, 2011 |
|
| Maximum 10-min Rain |
0.2 mm |
|
|
1.4 mm, 2011 |
|
| Maximum Rain Rate |
n/a |
|
|
15, 2011 |
|
| Minimum Dew Point |
9.9 °C |
17:32 |
9.6 °C |
15.6 °C, 2018 |
2.6 °C, 2014 |
| Maximum Dew Point |
13.7 °C |
19:29 |
14.9 °C |
19.2 °C, 2020 |
8.6 °C, 2014 |
| Mean Dew Point |
11.8 °C |
|
12.3 °C |
16.6 °C, 2018 |
5.3 °C, 2014 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 15.9 °C * |
05:55 |
15.8 °C |
18.4 °C, 2018 |
8.6 °C, 2014 |
| Day Maximum (09-21) |
23.8 °C |
15:29 |
28.3 °C |
24.9 °C, 2012 |
18.9 °C, 2014 |
| Max 10m Temp Rise |
0.9 °C |
12:29 |
0.8 °C |
0.9 °C, 2026 |
0.4 °C, 2010 |
| Max 1hr Temp Rise |
2.2 °C |
12:44 |
3.1 °C |
2.9 °C, 2013 |
1.2 °C, 2010 |
| Max 1hr Hum Rise |
26% |
18:41 |
12% |
26%, 2026 |
4%, 2010 |
| Max 10m Temp Fall |
1.2 °C |
17:10 |
0.8 °C |
1.2 °C, 2026 |
0.2 °C, 2010 |
| Max 1hr Temp Fall |
3.4 °C |
18:44 |
2.5 °C |
3.4 °C, 2026 |
0.4 °C, 2010 |
| Max 1hr Hum Fall |
11% |
09:37 |
12% |
15%, 2013 |
2%, 2010 |
| Max 10m Wind Speed |
12.3 mph |
15:11 |
9.0 mph |
21.9 mph, 2016 |
6.3 mph, 2013 |
| Minimum Feels-like |
17.4 °C |
23:58 |
17.6 °C |
22.7 °C, 2018 |
6.9 °C, 2014 |
| Maximum Feels-like |
25.7 °C |
13:48 |
31.2 °C |
31.1 °C, 2018 |
18.9 °C, 2014 |
| Mean Feels-like |
20.9 °C |
|
24.8 °C |
26.7 °C, 2018 |
13.8 °C, 2014 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
0 |
10:25 |
2 |
0, 2026 |
0, 2021 |
| Maximum PM2.5 |
6 |
19:35 |
12 |
6, 2026 |
6, 2026 |
| Mean PM2.5 |
2 |
|
6 |
2, 2026 |
2, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
8.3 °C (-0.1) |
12.6 °C (+4.1) |
13.1 °C (+4.7), 2013 |
4.2 °C (-4.2), 2010 |
| Humidity Range |
36% |
42% |
50%, 2020 |
16%, 2010 |
| Pressure Range |
6 hPa |
5 hPa |
8 hPa, 2009 |
2 hPa, 2025 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
7.6 [58%] | 199 hrs (163%) [74%] |
11 [84%], 2020 |
0.2 [2%], 2015 |
| Wet Hours |
1 [Mean rain rate: 0.4 mm/h] | 5 hrs (20%) [1%] |
4, 2017 |
0, 2009 |
| Cloud Cover |
unknown |
| Events |
None |
| Comments |
data is awaiting quality control from site operator |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
23.0 °C |