| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
0.4 °C (-2.5) |
23:49 |
1.6 °C (-1.3) |
8.3 °C (+5.4), 2011 |
-5.1 °C (-8.0), 2012 |
| Maximum Temperature |
4.9 °C (-3.0) |
10:51 |
6.3 °C (-1.6) |
11.4 °C (+3.5), 2024 |
1.6 °C (-6.3), 2012 |
| Mean Temperature |
3.2 °C (-2.8) |
|
4.2 °C (-1.4) |
9.8 °C, 2024 |
-0.7 °C, 2012 |
| Minimum Humidity |
89% |
00:03 |
63% |
89%, 2013 |
55%, 2009 |
| Maximum Humidity |
98% |
23:59 |
90% |
98%, 2009 |
83%, 2016 |
| Mean Humidity |
95% |
|
77% |
95%, 2013 |
75%, 2016 |
| Minimum Pressure |
991 hPa |
20:39 |
1004 hPa |
1037 hPa, 2012 |
977 hPa, 2009 |
| Maximum Pressure |
1012 hPa |
00:08 |
1017 hPa |
1039 hPa, 2012 |
986 hPa, 2024 |
| Mean Pressure |
999 hPa |
|
1011 hPa |
1038 hPa, 2012 |
984 hPa, 2024 |
| Mean Wind Speed |
5.1 mph (-0.0) |
|
5.7 mph (+0.6) |
12.9 mph, 2020 |
1.9 mph, 2012 |
| Maximum Wind Speed |
14.7 mph |
14:15 |
15.2 mph |
28.0 mph, 2020 |
8.3 mph, 2024 |
| Maximum Gust |
21.9 mph |
12:52 |
21.9 mph |
46.1 mph, 2020 |
10.9 mph, 2012 |
| Mean Wind Direction |
SSE |
|
|
|
|
| Rainfall / Snow-melt approx. |
12.9 mm |
|
25.2 mm (157%) |
12.9 mm, 2013 |
|
| Maximum Hourly Rain |
1.9 mm |
17:11 |
|
4.2 mm, 2020 |
|
| Maximum 10-min Rain |
0.7 mm |
17:34 |
|
2.0 mm, 2020 |
|
| Maximum Rain Rate |
3.0 mm/h |
17:02 |
|
30 mm/h, 2020 |
|
| Minimum Dew Point |
0.1 °C |
21:37 |
-3.0 °C |
7.0 °C, 2024 |
-8.6 °C, 2012 |
| Maximum Dew Point |
4.2 °C |
10:35 |
3.7 °C |
10.1 °C, 2011 |
-2.4 °C, 2021 |
| Mean Dew Point |
2.4 °C |
|
0.4 °C |
8.5 °C, 2011 |
-4.1 °C, 2012 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
* 3.2 °C * |
00:32 |
2.5 °C |
8.4 °C, 2024 |
-1.8 °C, 2021 |
| Day Maximum (09-21) |
4.9 °C |
10:51 |
6.1 °C |
11.4 °C, 2024 |
1.6 °C, 2012 |
| Max 10m Temp Rise |
0.1 °C |
03:32 |
0.3 °C |
0.8 °C, 2023 |
0.1 °C, 2011 |
| Max 1hr Temp Rise |
0.5 °C |
02:39 |
1.1 °C |
2.4 °C, 2023 |
0.3 °C, 2017 |
| Max 1hr Hum Rise |
3% |
01:01 |
8% |
15%, 2010 |
2%, 2015 |
| Max 10m Temp Fall |
0.2 °C |
14:54 |
0.4 °C |
1.7 °C, 2020 |
0.1 °C, 2011 |
| Max 1hr Temp Fall |
1.0 °C |
17:27 |
1.1 °C |
3.6 °C, 2020 |
0.4 °C, 2011 |
| Max 1hr Hum Fall |
2% |
11:18 |
9% |
14%, 2014 |
2%, 2011 |
| Max 10m Wind Speed |
11.0 mph |
14:22 |
11.2 mph |
19.5 mph, 2020 |
5.6 mph, 2024 |
| Minimum Feels-like |
-4.4 °C |
21:50 |
-2.9 °C |
6.5 °C, 2024 |
-8.4 °C, 2012 |
| Maximum Feels-like |
4.6 °C |
05:51 |
5.8 °C |
12.4 °C, 2024 |
-0.1 °C, 2021 |
| Mean Feels-like |
0.5 °C |
|
1.5 °C |
9.7 °C, 2024 |
-4.1 °C, 2021 |
| Air-frost Hrs |
0 hrs |
|
0.0 hrs |
16 hrs, 2021 |
0 hrs, 2011 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
4.5 °C (-0.5) |
4.7 °C (-0.2) |
10.6 °C (+5.6), 2018 |
0.9 °C (-4.1), 2017 |
| Humidity Range |
9% |
27% |
43%, 2009 |
9%, 2013 |
| Pressure Range |
21 hPa |
13 hPa |
36 hPa, 2009 |
2 hPa, 2012 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0 [0%] | 24 hrs (92%) [29%] |
5 [58%], 2021 |
0 [0%], 2011 |
| Wet Hours |
23 [Mean rain rate: 0.6 mm/h] | 41 hrs (221%) [17%] |
23, 2013 |
, 2009 |
| Cloud Cover |
Overcast |
| Events |
Snowfall: ~3 cm |
| Comments |
00-24 Drizzle/Rain (->Snow at approx. 18) |
| Extra Comments |
1cm lying snow by 23z |
| Issues |
wind sensor froze (from snow) at 23z |
| Observer Absent? |
No |
| Pond Temperature @ Hampstead Heath |
0.0 °C |