| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
5.2 °C (+2.3) |
23:13 |
4.4 °C (+1.3) |
8.9 °C (+6.0), 2021 |
-0.7 °C (-3.6), 2019 |
| Maximum Temperature |
9.1 °C (+1.3) |
12:51 |
9.7 °C (+1.9) |
12.9 °C (+5.1), 2018 |
1.2 °C (-6.6), 2011 |
| Mean Temperature |
6.5 °C (+1.8) |
|
7.1 °C (+1.6) |
11.1 °C, 2018 |
0.5 °C, 2011 |
| Minimum Humidity |
72% |
13:02 |
74% |
83%, 2025 |
51%, 2015 |
| Maximum Humidity |
91% |
23:53 |
95% |
97%, 2021 |
76%, 2011 |
| Mean Humidity |
83% |
|
87% |
91%, 2021 |
64%, 2011 |
| Minimum Pressure |
983 hPa |
13:43 |
996 hPa |
1032 hPa, 2023 |
979 hPa, 2025 |
| Maximum Pressure |
989 hPa |
23:25 |
1006 hPa |
1037 hPa, 2022 |
989 hPa, 2014 |
| Mean Pressure |
985 hPa |
|
1001 hPa |
1035 hPa, 2022 |
985 hPa, 2025 |
| Mean Wind Speed |
6.5 mph (+1.3) |
|
6.0 mph (+0.8) |
9.4 mph, 2015 |
2.0 mph, 2023 |
| Maximum Wind Speed |
16.8 mph |
16:03 |
15.7 mph |
25.9 mph, 2013 |
6.7 mph, 2023 |
| Maximum Gust |
24.6 mph |
16:03 |
23.3 mph |
42.6 mph, 2025 |
10.4 mph, 2023 |
| Mean Wind Direction |
S |
|
|
|
|
| Rainfall |
3.7 mm |
|
117.8 mm (221%) |
19.9 mm, 2021 |
|
| Maximum Hourly Rain |
3.4 mm |
22:57 |
|
4.6 mm, 2021 |
|
| Maximum 10-min Rain |
1.5 mm |
22:46 |
|
1.5 mm, 2014 |
|
| Maximum Rain Rate |
18 mm/h |
22:39 |
|
24 mm/h, 2015 |
|
| Minimum Dew Point |
2.2 °C |
17:34 |
2.1 °C |
8.1 °C, 2021 |
-6.5 °C, 2011 |
| Maximum Dew Point |
5.5 °C |
10:36 |
8.2 °C |
10.3 °C, 2018 |
-3.8 °C, 2011 |
| Mean Dew Point |
3.9 °C |
|
4.9 °C |
9.3 °C, 2021 |
-5.6 °C, 2011 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 4.6 °C * |
21:11 |
5.3 °C |
8.9 °C, 2021 |
0.4 °C, 2011 |
| Day Maximum (09-21) |
9.1 °C |
12:51 |
9.3 °C |
12.9 °C, 2018 |
1.2 °C, 2011 |
| Max 10m Temp Rise |
0.4 °C |
10:35 |
0.3 °C |
0.4 °C, 2010 |
0.1 °C, 2011 |
| Max 1hr Temp Rise |
1.5 °C |
10:55 |
1.3 °C |
1.9 °C, 2024 |
0.3 °C, 2011 |
| Max 1hr Hum Rise |
6% |
18:17 |
7% |
9%, 2013 |
2%, 2018 |
| Max 10m Temp Fall |
0.3 °C |
12:09 |
0.5 °C |
1.9 °C, 2015 |
0.2 °C, 2010 |
| Max 1hr Temp Fall |
1.2 °C |
16:36 |
1.3 °C |
2.9 °C, 2015 |
0.6 °C, 2018 |
| Max 1hr Hum Fall |
10% |
11:32 |
10% |
18%, 2015 |
3%, 2011 |
| Max 10m Wind Speed |
11.3 mph |
11:32 |
11.4 mph |
16.8 mph, 2013 |
5.1 mph, 2023 |
| Minimum Feels-like |
1.2 °C |
22:37 |
0.9 °C |
6.7 °C, 2021 |
-6.0 °C, 2011 |
| Maximum Feels-like |
7.3 °C |
12:15 |
9.7 °C |
14.3 °C, 2018 |
0.2 °C, 2011 |
| Mean Feels-like |
3.8 °C |
|
5.3 °C |
11.3 °C, 2021 |
-3.7 °C, 2011 |
| Air-frost Hrs |
0 hrs |
|
0.3 hrs |
5 hrs, 2011 |
0 hrs, 2010 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
3.9 °C (-0.9) |
5.3 °C (+0.5) |
8.0 °C (+3.2), 2013 |
1.7 °C (-3.1), 2011 |
| Humidity Range |
19% |
21% |
44%, 2015 |
11%, 2025 |
| Pressure Range |
6 hPa |
10 hPa |
20 hPa, 2015 |
2 hPa, 2009 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
3.5 [44%] | 68 hrs (110%) [33%] |
8 [100%], 2019 |
0 [0%], 2009 |
| Wet Hours |
2 [Mean rain rate: 1.9 mm/h] | 89 hrs (148%) [13%] |
9, 2021 |
, 2009 |
| Cloud Cover |
Partly Cloudy or Mostly Cloudy |
| Events |
None |
| Comments |
17- Slight Showers (2230 Heavy) |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
No |
| Pond Temperature @ Hampstead Heath |
0.0 °C |