| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
8.9 °C (+1.8) |
06:17 |
8.9 °C (+1.7) |
11.2 °C (+4.1), 2024 |
1.5 °C (-5.6), 2016 |
| Maximum Temperature |
25.6 °C (+9.5) |
14:12 |
25.6 °C (+9.4) |
28.7 °C (+12.6), 2025 |
12.3 °C (-3.8), 2021 |
| Mean Temperature |
17.5 °C (+5.7) |
|
17.5 °C (+5.5) |
19.8 °C, 2025 |
7.6 °C, 2021 |
| Minimum Humidity |
34% |
13:27 |
34% |
72%, 2014 |
26%, 2025 |
| Maximum Humidity |
72% |
02:30 |
72% |
97%, 2012 |
66%, 2011 |
| Mean Humidity |
55% |
|
55% |
90%, 2014 |
52%, 2011 |
| Minimum Pressure |
1020 hPa |
18:12 |
1020 hPa |
1026 hPa, 2016 |
997 hPa, 2020 |
| Maximum Pressure |
1022 hPa |
00:29 |
1022 hPa |
1029 hPa, 2016 |
1006 hPa, 2020 |
| Mean Pressure |
1021 hPa |
|
1021 hPa |
1027 hPa, 2016 |
1000 hPa, 2020 |
| Mean Wind Speed |
4.3 mph (-0.4) |
|
4.3 mph (-0.4) |
9.2 mph, 2011 |
1.6 mph, 2014 |
| Maximum Wind Speed |
12.1 mph |
17:36 |
12.1 mph |
18.5 mph, 2011 |
8.5 mph, 2014 |
| Maximum Gust |
19.6 mph |
15:49 |
19.6 mph |
27.3 mph, 2011 |
12.3 mph, 2014 |
| Mean Wind Direction |
S |
|
|
|
|
| Rainfall |
0.0 mm |
|
0.0 mm (0%) |
31.7 mm, 2010 |
|
| Maximum Hourly Rain |
n/a |
|
|
13.1, 2010 |
|
| Maximum 10-min Rain |
n/a |
|
|
4.1, 2010 |
|
| Maximum Rain Rate |
n/a |
|
|
60, 2010 |
|
| Minimum Dew Point |
3.0 °C |
06:09 |
3.0 °C |
10.3 °C, 2024 |
-2.7 °C, 2013 |
| Maximum Dew Point |
14.4 °C |
17:28 |
14.4 °C |
14.6 °C, 2024 |
2.8 °C, 2015 |
| Mean Dew Point |
7.9 °C |
|
7.9 °C |
12.3 °C, 2024 |
0.8 °C, 2013 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
8.9 °C |
06:17 |
8.9 °C |
11.2 °C, 2024 |
1.5 °C, 2016 |
| Day Maximum (09-21) |
25.6 °C |
14:59 |
25.6 °C |
28.7 °C, 2025 |
12.3 °C, 2021 |
| Max 10m Temp Rise |
0.9 °C |
06:43 |
0.9 °C |
1.6 °C, 2009 |
0.3 °C, 2014 |
| Max 1hr Temp Rise |
3.9 °C |
07:28 |
3.9 °C |
4.5 °C, 2016 |
0.7 °C, 2014 |
| Max 1hr Hum Rise |
8% |
17:04 |
8% |
18%, 2020 |
4%, 2014 |
| Max 10m Temp Fall |
0.6 °C |
17:38 |
0.6 °C |
2.4 °C, 2020 |
0.3 °C, 2014 |
| Max 1hr Temp Fall |
2.0 °C |
20:24 |
2.0 °C |
3.3 °C, 2020 |
0.7 °C, 2014 |
| Max 1hr Hum Fall |
14% |
07:43 |
14% |
22%, 2013 |
3%, 2014 |
| Max 10m Wind Speed |
9.4 mph |
19:57 |
9.4 mph |
13.0 mph, 2018 |
5.6 mph, 2025 |
| Minimum Feels-like |
7.4 °C |
04:16 |
7.4 °C |
12.6 °C, 2024 |
-0.9 °C, 2018 |
| Maximum Feels-like |
28.1 °C |
15:48 |
28.1 °C |
30.0 °C, 2025 |
12.3 °C, 2021 |
| Mean Feels-like |
18.4 °C |
|
18.4 °C |
21.1 °C, 2025 |
7.1 °C, 2021 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
16.7 °C (+7.7) |
16.7 °C (+7.7) |
19.1 °C (+10.1), 2025 |
3.2 °C (-5.8), 2014 |
| Humidity Range |
38% |
38% |
62%, 2025 |
17%, 2017 |
| Pressure Range |
3 hPa |
3 hPa |
16 hPa, 2017 |
2 hPa, 2010 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
13.5 [101%] | 14 hrs (234%) [100%] |
13.5 [101%], 2026 |
0 [0%], 2014 |
| Wet Hours |
0 | 0 hrs (0%) [0%] |
13, 2014 |
0, 2009 |
| Cloud Cover |
unknown |
| Events |
Maximum possible sunshine |
| 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 |
17.5 °C |