Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
Minimum Temperature |
1.1 °C (-1.6) |
23:55 |
4.3 °C (+1.4) |
11.3 °C (+8.6), 2024 |
-1.5 °C (-4.2), 2009 |
Maximum Temperature |
5.8 °C (-2.3) |
13:30 |
9.0 °C (+1.0) |
13.3 °C (+5.2), 2024 |
4.3 °C (-3.8), 2010 |
Mean Temperature |
3.5 °C (-2.0) |
|
6.9 °C (+1.2) |
12.3 °C, 2024 |
2.2 °C, 2010 |
Minimum Humidity |
51% |
16:38 |
62% |
91%, 2024 |
48%, 2009 |
Maximum Humidity |
92% |
04:02 |
86% |
98%, 2013 |
78%, 2017 |
Mean Humidity |
75% |
|
76% |
92%, 2024 |
68%, 2021 |
Minimum Pressure |
986 hPa |
00:29 |
997 hPa |
1030 hPa, 2019 |
975 hPa, 2014 |
Maximum Pressure |
1010 hPa |
23:10 |
1008 hPa |
1034 hPa, 2019 |
1000 hPa, 2014 |
Mean Pressure |
996 hPa |
|
1002 hPa |
1032 hPa, 2019 |
989 hPa, 2014 |
Mean Wind Speed |
6.0 mph (+0.9) |
|
7.5 mph (+2.4) |
10.6 mph, 2014 |
1.0 mph, 2023 |
Maximum Wind Speed |
14.0 mph |
00:00 |
17.8 mph |
35.5 mph, 2014 |
6.0 mph, 2023 |
Maximum Gust |
22.0 mph |
00:00 |
25.7 mph |
49.7 mph, 2014 |
9.2 mph, 2023 |
Mean Wind Direction |
NNE |
|
|
|
|
Rainfall |
0.7 mm |
|
23.0 mm (106%) |
8.5 mm, 2014 |
|
Maximum Hourly Rain |
0.3 mm |
01:54 |
|
4.6 mm, 2014 |
|
Maximum 10-min Rain |
0.2 mm |
|
|
1.5 mm, 2014 |
|
Maximum Rain Rate |
n/a |
|
|
18, 2014 |
|
Minimum Dew Point |
-5.9 °C |
18:47 |
-0.2 °C |
10.0 °C, 2024 |
-5.9 °C, 2016 |
Maximum Dew Point |
2.3 °C |
00:15 |
5.4 °C |
11.9 °C, 2024 |
-1.1 °C, 2025 |
Mean Dew Point |
-0.8 °C |
|
2.9 °C |
11.1 °C, 2024 |
-2.6 °C, 2021 |
Measure | Value | Time |
Month cumul. | Record High | Record Low |
Night Minimum (21-09) |
* 2.4 °C * |
06:22 |
5.2 °C |
11.3 °C, 2024 |
-1.5 °C, 2009 |
Day Maximum (09-21) |
5.8 °C |
13:30 |
9.0 °C |
13.3 °C, 2024 |
4.3 °C, 2010 |
Max 10m Temp Rise |
0.4 °C |
11:01 |
0.3 °C |
0.9 °C, 2019 |
0.2 °C, 2010 |
Max 1hr Temp Rise |
1.1 °C |
11:19 |
1.1 °C |
3.2 °C, 2023 |
0.5 °C, 2024 |
Max 1hr Hum Rise |
8% |
20:59 |
7% |
14%, 2021 |
2%, 2024 |
Max 10m Temp Fall |
0.2 °C |
05:54 |
0.4 °C |
0.9 °C, 2022 |
0.1 °C, 2024 |
Max 1hr Temp Fall |
0.9 °C |
16:29 |
1.1 °C |
3.0 °C, 2023 |
0.4 °C, 2017 |
Max 1hr Hum Fall |
13% |
12:56 |
9% |
19%, 2014 |
2%, 2024 |
Max 10m Wind Speed |
10.5 mph |
00:10 |
13.6 mph |
26.6 mph, 2014 |
5.0 mph, 2023 |
Minimum Feels-like |
-3.4 °C |
23:52 |
-0.0 °C |
12.6 °C, 2024 |
-5.3 °C, 2021 |
Maximum Feels-like |
2.4 °C |
13:17 |
7.6 °C |
15.5 °C, 2024 |
2.3 °C, 2021 |
Mean Feels-like |
-0.5 °C |
|
4.4 °C |
14.1 °C, 2024 |
-1.8 °C, 2021 |
Air-frost Hrs |
0 hrs |
|
0 hrs |
6 hrs, 2009 |
0 hrs, 2010 |
Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
Temperature Range |
4.7 °C (-0.6) |
4.7 °C (-0.3) |
12.7 °C (+7.4), 2019 |
2.0 °C (-3.3), 2024 |
Humidity Range |
41% |
25% |
48%, 2009 |
3%, 2024 |
Pressure Range |
24 hPa |
11 hPa |
25 hPa, 2014 |
3 hPa, 2025 |
Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
Sun Hours |
2.4 [27%] | 26 hrs (70%) [22%] |
8.9 [100%], 2019 |
0 [0%], 2014 |
Wet Hours |
3 [Mean rain rate: 0.2 mm/h] | 31 hrs (124%) [9.3%] |
8, 2018 |
, 2009 |
Cloud Cover |
Partly Cloudy or Hazy |
Events |
None |
Comments |
o.night Rain |
Extra Comments |
|
Issues |
No wind data all day; corrected using Harpenden |
Observer Absent? |
Yes - observations may be unreliable |
Pond Temperature @ Hampstead Heath |
0.0 °C |