| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
16.7 °C (+2.7) |
06:27 |
15.8 °C (+1.4) |
17.7 °C (+3.7), 2012 |
9.1 °C (-4.9), 2011 |
| Maximum Temperature |
25.6 °C (+3.3) |
16:55 |
28.6 °C (+5.7) |
29.5 °C (+7.2), 2012 |
18.1 °C (-4.2), 2014 |
| Mean Temperature |
20.2 °C (+3.0) |
|
22.4 °C (+3.6) |
23.6 °C, 2012 |
13.8 °C, 2014 |
| Minimum Humidity |
39% |
18:57 |
36% |
85%, 2020 |
35%, 2009 |
| Maximum Humidity |
86% |
05:20 |
78% |
97%, 2011 |
76%, 2014 |
| Mean Humidity |
65% |
|
56% |
92%, 2020 |
56%, 2013 |
| Minimum Pressure |
1004 hPa |
18:06 |
1016 hPa |
1018 hPa, 2018 |
1000 hPa, 2020 |
| Maximum Pressure |
1011 hPa |
00:00 |
1021 hPa |
1026 hPa, 2013 |
1009 hPa, 2016 |
| Mean Pressure |
1006 hPa |
|
1018 hPa |
1019 hPa, 2018 |
1005 hPa, 2020 |
| Mean Wind Speed |
5.2 mph (+1.2) |
|
3.9 mph (-0.1) |
7.1 mph, 2023 |
2.6 mph, 2012 |
| Maximum Wind Speed |
15.3 mph |
18:31 |
12.3 mph |
22.3 mph, 2016 |
9.2 mph, 2012 |
| Maximum Gust |
25.3 mph |
20:00 |
18.6 mph |
30.6 mph, 2016 |
12.5 mph, 2013 |
| Mean Wind Direction |
WNW |
|
|
|
|
| Rainfall |
1.0 mm |
|
1.6 mm (5%) |
11.5 mm, 2020 |
|
| Maximum Hourly Rain |
0.6 mm |
04:04 |
|
3.5 mm, 2020 |
|
| Maximum 10-min Rain |
0.2 mm |
04:04 |
|
0.9 mm, 2015 |
|
| Maximum Rain Rate |
0.4 mm/h |
04:04 |
|
18 mm/h, 2015 |
|
| Minimum Dew Point |
8.4 °C |
21:08 |
9.6 °C |
14.6 °C, 2023 |
4.1 °C, 2014 |
| Maximum Dew Point |
14.9 °C |
01:27 |
15.0 °C |
19.8 °C, 2012 |
8.5 °C, 2014 |
| Mean Dew Point |
12.9 °C |
|
12.4 °C |
16.8 °C, 2020 |
5.7 °C, 2014 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
16.7 °C |
06:31 |
15.8 °C |
19.1 °C, 2022 |
9.1 °C, 2011 |
| Day Maximum (09-21) |
25.6 °C |
16:56 |
28.6 °C |
29.5 °C, 2012 |
18.1 °C, 2014 |
| Max 10m Temp Rise |
0.8 °C |
11:39 |
0.8 °C |
0.9 °C, 2012 |
0.2 °C, 2016 |
| Max 1hr Temp Rise |
2.2 °C |
13:57 |
3.1 °C |
3.2 °C, 2012 |
0.7 °C, 2016 |
| Max 1hr Hum Rise |
9% |
22:09 |
12% |
16%, 2012 |
3%, 2020 |
| Max 10m Temp Fall |
0.8 °C |
19:07 |
0.8 °C |
1.0 °C, 2019 |
0.3 °C, 2020 |
| Max 1hr Temp Fall |
2.6 °C |
19:54 |
2.5 °C |
2.6 °C, 2013 |
0.9 °C, 2021 |
| Max 1hr Hum Fall |
10% |
12:18 |
12% |
17%, 2013 |
3%, 2020 |
| Max 10m Wind Speed |
11.6 mph |
19:06 |
8.8 mph |
16.2 mph, 2016 |
6.7 mph, 2012 |
| Minimum Feels-like |
19.1 °C |
23:55 |
17.6 °C |
22.3 °C, 2012 |
7.9 °C, 2011 |
| Maximum Feels-like |
28.1 °C |
16:28 |
31.5 °C |
34.7 °C, 2012 |
18.1 °C, 2014 |
| Mean Feels-like |
23.0 °C |
|
25.0 °C |
28.7 °C, 2012 |
13.8 °C, 2014 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
2 |
23:56 |
3 |
2, 2026 |
0, 2021 |
| Maximum PM2.5 |
12 |
22:55 |
13 |
12, 2026 |
12, 2026 |
| Mean PM2.5 |
4 |
|
6 |
4, 2026 |
4, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
8.9 °C (+0.6) |
12.8 °C (+4.3) |
14.6 °C (+6.3), 2009 |
3.1 °C (-5.2), 2016 |
| Humidity Range |
47% |
42% |
52%, 2009 |
9%, 2016 |
| Pressure Range |
7 hPa |
5 hPa |
14 hPa, 2013 |
2 hPa, 2021 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
5.8 [44%] | 192 hrs (165%) [74%] |
10.5 [80%], 2009 |
0 [0%], 2020 |
| Wet Hours |
3 [Mean rain rate: 0.3 mm/h] | 4 hrs (17%) [0.9%] |
8, 2020 |
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 |