Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
Minimum Temperature |
2.6 °C (-0.2) |
07:46 |
4.8 °C (+1.9) |
7.2 °C (+4.4), 2023 |
-5.7 °C (-8.5), 2012 |
Maximum Temperature |
5.6 °C (-2.4) |
10:31 |
9.6 °C (+1.7) |
11.1 °C (+3.1), 2019 |
0.9 °C (-7.1), 2021 |
Mean Temperature |
4.2 °C (-1.3) |
|
7.5 °C (+1.8) |
8.9 °C, 2011 |
-0.9 °C, 2021 |
Minimum Humidity |
77% |
17:48 |
61% |
80%, 2012 |
57%, 2022 |
Maximum Humidity |
88% |
09:11 |
86% |
98%, 2013 |
76%, 2015 |
Mean Humidity |
82% |
|
75% |
88%, 2010 |
71%, 2021 |
Minimum Pressure |
993 hPa |
23:45 |
999 hPa |
1037 hPa, 2023 |
985 hPa, 2014 |
Maximum Pressure |
1000 hPa |
00:30 |
1009 hPa |
1039 hPa, 2023 |
1000 hPa, 2016 |
Mean Pressure |
994 hPa |
|
1004 hPa |
1038 hPa, 2023 |
993 hPa, 2014 |
Mean Wind Speed |
1.9 mph (-3.2) |
|
7.9 mph (+2.8) |
10.2 mph, 2014 |
1.0 mph, 2012 |
Maximum Wind Speed |
8.7 mph |
00:00 |
18.6 mph |
29.7 mph, 2014 |
6.1 mph, 2025 |
Maximum Gust |
11.5 mph |
00:00 |
26.8 mph |
47.8 mph, 2014 |
10.2 mph, 2012 |
Mean Wind Direction |
SE |
|
|
|
|
Rainfall |
0.0 mm |
|
20.2 mm (108%) |
6.7 mm, 2014 |
|
Maximum Hourly Rain |
n/a |
|
|
3.7, 2014 |
|
Maximum 10-min Rain |
n/a |
|
|
1.2, 2014 |
|
Maximum Rain Rate |
n/a |
|
|
9, 2014 |
|
Minimum Dew Point |
-0.1 °C |
03:37 |
0.3 °C |
4.3 °C, 2023 |
-8.5 °C, 2012 |
Maximum Dew Point |
3.8 °C |
10:11 |
5.9 °C |
9.7 °C, 2011 |
-4.3 °C, 2021 |
Mean Dew Point |
1.4 °C |
|
3.3 °C |
6.5 °C, 2011 |
-5.5 °C, 2021 |
Measure | Value | Time |
Month cumul. | Record High | Record Low |
Night Minimum (21-09) |
2.6 °C |
07:46 |
5.8 °C |
8.7 °C, 2011 |
-5.7 °C, 2012 |
Day Maximum (09-21) |
5.6 °C |
10:31 |
9.6 °C |
11.1 °C, 2019 |
0.9 °C, 2021 |
Max 10m Temp Rise |
0.5 °C |
08:41 |
0.3 °C |
0.6 °C, 2025 |
0.1 °C, 2013 |
Max 1hr Temp Rise |
1.7 °C |
09:24 |
1.2 °C |
2.1 °C, 2019 |
0.3 °C, 2013 |
Max 1hr Hum Rise |
3% |
20:35 |
7% |
18%, 2009 |
1%, 2013 |
Max 10m Temp Fall |
0.3 °C |
03:33 |
0.4 °C |
0.6 °C, 2025 |
0.1 °C, 2013 |
Max 1hr Temp Fall |
0.9 °C |
06:45 |
1.2 °C |
1.8 °C, 2009 |
0.3 °C, 2013 |
Max 1hr Hum Fall |
4% |
10:58 |
9% |
18%, 2014 |
3%, 2015 |
Max 10m Wind Speed |
10.5 mph |
00:10 |
14.1 mph |
22.2 mph, 2014 |
4.2 mph, 2025 |
Minimum Feels-like |
-1.6 °C |
03:43 |
0.5 °C |
4.3 °C, 2023 |
-10.4 °C, 2021 |
Maximum Feels-like |
2.2 °C |
10:11 |
8.6 °C |
11.7 °C, 2011 |
-2.0 °C, 2021 |
Mean Feels-like |
0.4 °C |
|
5.2 °C |
7.9 °C, 2011 |
-5.8 °C, 2021 |
Air-frost Hrs |
0 hrs |
|
0 hrs |
20 hrs, 2021 |
0 hrs, 2010 |
Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
Temperature Range |
3.0 °C (-2.2) |
4.8 °C (-0.2) |
10.1 °C (+4.9), 2012 |
1.1 °C (-4.1), 2015 |
Humidity Range |
11% |
25% |
38%, 2009 |
5%, 2023 |
Pressure Range |
7 hPa |
10 hPa |
18 hPa, 2014 |
2 hPa, 2019 |
Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
Sun Hours |
1 [11%] | 24 hrs (74%) [23%] |
8.4 [96%], 2024 |
0 [0%], 2012 |
Wet Hours |
0 | 16 hrs (75%) [5.6%] |
3.5, 2014 |
, 2009 |
Cloud Cover |
am: Partly Cloudy transitioned to Overcast pm: Overcast |
Events |
None |
Comments |
- |
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 |