| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
5.8 °C (+2.8) |
08:13 |
5.1 °C (+2.1) |
11.3 °C (+8.3), 2011 |
0.3 °C (-2.7), 2012 |
| Maximum Temperature |
8.3 °C (+0.5) |
22:38 |
8.7 °C (+0.8) |
13.0 °C (+5.2), 2011 |
2.2 °C (-5.6), 2012 |
| Mean Temperature |
7.0 °C (+1.7) |
|
6.8 °C (+1.5) |
12.0 °C, 2011 |
1.0 °C, 2012 |
| Minimum Humidity |
83% |
02:03 |
82% |
89%, 2012 |
45%, 2013 |
| Maximum Humidity |
96% |
22:20 |
95% |
98%, 2015 |
83%, 2011 |
| Mean Humidity |
92% |
|
90% |
94%, 2012 |
68%, 2013 |
| Minimum Pressure |
983 hPa |
18:56 |
992 hPa |
1041 hPa, 2023 |
978 hPa, 2014 |
| Maximum Pressure |
987 hPa |
00:00 |
996 hPa |
1047 hPa, 2023 |
987 hPa, 2026 |
| Mean Pressure |
984 hPa |
|
994 hPa |
1045 hPa, 2023 |
983 hPa, 2014 |
| Mean Wind Speed |
6.9 mph (+1.8) |
|
5.7 mph (+0.6) |
11.9 mph, 2014 |
0.6 mph, 2012 |
| Maximum Wind Speed |
14.2 mph |
00:45 |
14.0 mph |
23.9 mph, 2014 |
6.8 mph, 2020 |
| Maximum Gust |
21.9 mph |
00:46 |
22.1 mph |
42.7 mph, 2014 |
9.2 mph, 2020 |
| Mean Wind Direction |
SE |
|
|
|
|
| Rainfall |
7.8 mm |
|
23.2 mm (289%) |
9.0 mm, 2009 |
|
| Maximum Hourly Rain |
1.8 mm |
21:35 |
|
2.8 mm, 2014 |
|
| Maximum 10-min Rain |
0.6 mm |
07:59 |
|
0.7 mm, 2014 |
|
| Maximum Rain Rate |
3.6 mm/h |
20:40 |
|
4.8 mm/h, 2021 |
|
| Minimum Dew Point |
4.1 °C |
03:12 |
3.7 °C |
7.4 °C, 2011 |
-5.8 °C, 2013 |
| Maximum Dew Point |
7.7 °C |
22:38 |
6.8 °C |
9.0 °C, 2016 |
0.4 °C, 2018 |
| Mean Dew Point |
5.8 °C |
|
5.3 °C |
7.9 °C, 2011 |
-1.3 °C, 2013 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
5.8 °C |
08:17 |
5.5 °C |
11.3 °C, 2011 |
-0.6 °C, 2012 |
| Day Maximum (09-21) |
* 8.2 °C * |
20:58 |
8.3 °C |
13.0 °C, 2011 |
2.2 °C, 2012 |
| Max 10m Temp Rise |
0.2 °C |
09:44 |
0.3 °C |
0.8 °C, 2023 |
0.1 °C, 2011 |
| Max 1hr Temp Rise |
0.4 °C |
12:06 |
0.8 °C |
2.8 °C, 2022 |
0.4 °C, 2011 |
| Max 1hr Hum Rise |
5% |
03:37 |
6% |
16%, 2013 |
2%, 2012 |
| Max 10m Temp Fall |
0.3 °C |
03:33 |
0.3 °C |
1.2 °C, 2025 |
0.2 °C, 2011 |
| Max 1hr Temp Fall |
0.8 °C |
03:39 |
0.9 °C |
1.8 °C, 2013 |
0.3 °C, 2012 |
| Max 1hr Hum Fall |
1% |
01:02 |
4% |
23%, 2015 |
1%, 2026 |
| Max 10m Wind Speed |
10.9 mph |
01:33 |
10.4 mph |
18.6 mph, 2014 |
5.1 mph, 2020 |
| Minimum Feels-like |
1.0 °C |
08:09 |
1.2 °C |
11.7 °C, 2011 |
-5.1 °C, 2018 |
| Maximum Feels-like |
8.4 °C |
21:15 |
8.1 °C |
13.5 °C, 2011 |
1.7 °C, 2018 |
| Mean Feels-like |
4.0 °C |
|
4.5 °C |
12.4 °C, 2011 |
-1.7 °C, 2015 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
2.5 °C (-2.3) |
3.6 °C (-1.3) |
7.9 °C (+3.1), 2025 |
1.7 °C (-3.1), 2011 |
| Humidity Range |
13% |
13% |
42%, 2015 |
7%, 2024 |
| Pressure Range |
4 hPa |
4 hPa |
17 hPa, 2017 |
3 hPa, 2021 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0 [0%] | 2.6 hrs (20%) [6.3%] |
8 [96%], 2020 |
0 [0%], 2009 |
| Wet Hours |
10 [Mean rain rate: 0.8 mm/h] | 30 hrs (323%) [25%] |
10, 2026 |
, 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 |
6.5 °C |