| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
7.8 °C (-3.3) |
06:27 |
13.8 °C (+1.9) |
14.7 °C (+3.6), 2024 |
7.8 °C (-3.3), 2026 |
| Maximum Temperature |
22.9 °C (+4.8) |
15:11 |
22.1 °C (+2.5) |
22.9 °C (+4.8), 2024 |
15.2 °C (-2.9), 2015 |
| Mean Temperature |
15.3 °C (+0.8) |
|
17.9 °C (+2.2) |
18.5 °C, 2024 |
12.7 °C, 2025 |
| Minimum Humidity |
40% |
15:02 |
53% |
79%, 2013 |
40%, 2026 |
| Maximum Humidity |
85% |
07:57 |
87% |
96%, 2023 |
82%, 2019 |
| Mean Humidity |
65% |
|
72% |
88%, 2023 |
65%, 2019 |
| Minimum Pressure |
1032 hPa |
20:16 |
1017 hPa |
1032 hPa, 2026 |
996 hPa, 2023 |
| Maximum Pressure |
1034 hPa |
10:36 |
1023 hPa |
1034 hPa, 2026 |
998 hPa, 2023 |
| Mean Pressure |
1033 hPa |
|
1020 hPa |
1033 hPa, 2026 |
997 hPa, 2023 |
| Mean Wind Speed |
1.0 mph (-2.9) |
|
4.9 mph (+1.0) |
10.6 mph, 2018 |
0.3 mph, 2020 |
| Maximum Wind Speed |
8.8 mph |
13:12 |
13.4 mph |
26.7 mph, 2018 |
5.5 mph, 2020 |
| Maximum Gust |
12.7 mph |
11:45 |
22.3 mph |
38.0 mph, 2018 |
10.4 mph, 2020 |
| Mean Wind Direction |
NW |
|
|
|
|
| Rainfall |
0.0 mm |
|
26.2 mm (75%) |
7.4 mm, 2023 |
|
| Maximum Hourly Rain |
n/a |
|
|
4.3, 2023 |
|
| Maximum 10-min Rain |
n/a |
|
|
2.4, 2023 |
|
| Maximum Rain Rate |
n/a |
|
|
42, 2023 |
|
| Minimum Dew Point |
5.1 °C |
06:26 |
9.9 °C |
13.7 °C, 2024 |
3.0 °C, 2025 |
| Maximum Dew Point |
11.0 °C |
18:45 |
15.0 °C |
17.0 °C, 2024 |
8.4 °C, 2025 |
| Mean Dew Point |
8.1 °C |
|
12.4 °C |
15.3 °C, 2024 |
6.3 °C, 2025 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
7.8 °C |
06:27 |
14.4 °C |
14.7 °C, 2024 |
7.8 °C, 2026 |
| Day Maximum (09-21) |
22.9 °C |
15:11 |
22.0 °C |
22.9 °C, 2024 |
15.2 °C, 2015 |
| Max 10m Temp Rise |
1.0 °C |
08:59 |
0.6 °C |
1.0 °C, 2026 |
0.2 °C, 2015 |
| Max 1hr Temp Rise |
4.6 °C |
09:36 |
2.3 °C |
4.6 °C, 2026 |
0.5 °C, 2015 |
| Max 1hr Hum Rise |
8% |
18:54 |
8% |
19%, 2012 |
4%, 2013 |
| Max 10m Temp Fall |
0.5 °C |
18:46 |
0.6 °C |
1.6 °C, 2018 |
0.2 °C, 2015 |
| Max 1hr Temp Fall |
2.6 °C |
19:36 |
1.8 °C |
3.5 °C, 2018 |
0.8 °C, 2022 |
| Max 1hr Hum Fall |
18% |
09:47 |
11% |
18%, 2026 |
4%, 2013 |
| Max 10m Wind Speed |
5.8 mph |
13:16 |
9.9 mph |
18.4 mph, 2018 |
2.4 mph, 2020 |
| Minimum Feels-like |
7.8 °C |
06:24 |
15.5 °C |
17.9 °C, 2024 |
6.7 °C, 2025 |
| Maximum Feels-like |
23.7 °C |
15:59 |
25.3 °C |
27.6 °C, 2024 |
16.4 °C, 2025 |
| Mean Feels-like |
16.0 °C |
|
20.5 °C |
22.7 °C, 2024 |
12.7 °C, 2025 |
| Air-frost Hrs |
0 hrs |
|
0 hrs |
0 hrs, 2009 |
0 hrs, 2009 |
| Minimum PM2.5 |
3 |
16:15 |
1 |
3, 2026 |
0, 2021 |
| Maximum PM2.5 |
20 |
23:22 |
14 |
20, 2026 |
20, 2026 |
| Mean PM2.5 |
10 |
|
4 |
10, 2026 |
10, 2026 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
15.1 °C (+8.0) |
8.3 °C (+0.6) |
15.1 °C (+8.0), 2026 |
3.9 °C (-3.2), 2015 |
| Humidity Range |
45% |
34% |
47%, 2009 |
15%, 2013 |
| Pressure Range |
3 hPa |
5 hPa |
22 hPa, 2018 |
2 hPa, 2011 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
10.9 [98%] | 119 hrs (113%) [48%] |
11.2 [101%], 2019 |
0 [0%], 2015 |
| Wet Hours |
0 | 26 hrs (91%) [5.2%] |
4, 2015 |
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 |
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