| Measure | Value (anomaly) | Time |
Month cumul. | Record High | Record Low |
| Minimum Temperature |
-5.7 °C (-8.5) |
02:00 |
-3.3 °C (-6.3) |
7.2 °C (+4.4), 2023 |
-5.7 °C (-8.5), 2012 |
| Maximum Temperature |
4.4 °C (-3.6) |
15:34 |
2.0 °C (-5.9) |
11.1 °C (+3.1), 2019 |
0.9 °C (-7.1), 2021 |
| Mean Temperature |
0.3 °C (-6.1) |
|
-0.5 °C (-6.1) |
8.9 °C, 2011 |
-0.9 °C, 2021 |
| Minimum Humidity |
80% |
00:09 |
64% |
80%, 2012 |
57%, 2022 |
| Maximum Humidity |
95% |
13:57 |
87% |
98%, 2013 |
76%, 2015 |
| Mean Humidity |
88% |
|
76% |
88%, 2010 |
71%, 2021 |
| Minimum Pressure |
1032 hPa |
07:35 |
1033 hPa |
1037 hPa, 2023 |
985 hPa, 2014 |
| Maximum Pressure |
1036 hPa |
11:57 |
1038 hPa |
1039 hPa, 2023 |
1000 hPa, 2016 |
| Mean Pressure |
1034 hPa |
|
1035 hPa |
1038 hPa, 2023 |
993 hPa, 2014 |
| Mean Wind Speed |
1.0 mph (-4.1) |
|
3.5 mph (-1.6) |
10.2 mph, 2014 |
1.0 mph, 2012 |
| Maximum Wind Speed |
6.9 mph |
|
10.8 mph |
29.7 mph, 2014 |
6.1 mph, 2025 |
| Maximum Gust |
10.2 mph |
13:03 |
15.0 mph |
47.8 mph, 2014 |
10.2 mph, 2012 |
| Mean Wind Direction |
NW |
|
|
|
|
| Rainfall |
trace |
|
15.1 mm (81%) |
6.7, 2014 |
|
| Maximum Hourly Rain |
n/a |
13:35 |
|
3.7, 2014 |
|
| Maximum 10-min Rain |
n/a |
13:35 |
|
1.2, 2014 |
|
| Maximum Rain Rate |
n/a |
13:36 |
|
9, 2014 |
|
| Minimum Dew Point |
-8.5 °C |
00:10 |
-7.5 °C |
4.3 °C, 2023 |
-8.5 °C, 2012 |
| Maximum Dew Point |
3.3 °C |
14:51 |
-1.5 °C |
9.7 °C, 2011 |
-4.3 °C, 2021 |
| Mean Dew Point |
-1.4 °C |
|
-4.3 °C |
6.5 °C, 2011 |
-5.5 °C, 2021 |
| Measure | Value | Time |
Month cumul. | Record High | Record Low |
| Night Minimum (21-09) |
-5.7 °C |
01:00 |
-2.7 °C |
8.7 °C, 2011 |
-5.7 °C, 2012 |
| Day Maximum (09-21) |
4.4 °C |
15:34 |
2.0 °C |
11.1 °C, 2019 |
0.9 °C, 2021 |
| Max 10m Temp Rise |
0.5 °C |
03:38 |
0.4 °C |
0.6 °C, 2025 |
0.1 °C, 2013 |
| Max 1hr Temp Rise |
1.9 °C |
11:25 |
1.4 °C |
2.1 °C, 2019 |
0.3 °C, 2013 |
| Max 1hr Hum Rise |
5% |
13:06 |
5% |
18%, 2009 |
1%, 2013 |
| Max 10m Temp Fall |
0.4 °C |
22:57 |
0.3 °C |
0.6 °C, 2025 |
0.1 °C, 2013 |
| Max 1hr Temp Fall |
1.7 °C |
23:19 |
1.2 °C |
1.8 °C, 2009 |
0.3 °C, 2013 |
| Max 1hr Hum Fall |
4% |
15:09 |
8% |
18%, 2014 |
3%, 2015 |
| Max 10m Wind Speed |
4.4 mph |
15:05 |
7.5 mph |
22.2 mph, 2014 |
4.2 mph, 2025 |
| Minimum Feels-like |
-8.6 °C |
04:17 |
-7.3 °C |
4.3 °C, 2023 |
-10.4 °C, 2021 |
| Maximum Feels-like |
4.4 °C |
15:19 |
1.5 °C |
11.7 °C, 2011 |
-2.0 °C, 2021 |
| Mean Feels-like |
-0.3 °C |
|
-2.4 °C |
7.9 °C, 2011 |
-5.8 °C, 2021 |
| Air-frost Hrs |
10 hrs |
|
12 hrs |
20 hrs, 2021 |
0 hrs, 2010 |
| Measure | Value (anomaly) |
Month cumul. | Record High | Record Low |
| Temperature Range |
10.1 °C (+4.9) |
5.3 °C (+0.4) |
10.1 °C (+4.9), 2012 |
1.1 °C (-4.1), 2015 |
| Humidity Range |
15% |
23% |
38%, 2009 |
5%, 2023 |
| Pressure Range |
4 hPa |
5 hPa |
18 hPa, 2014 |
2 hPa, 2019 |
| Measure | Value [% of max] |
Month cumul. | Record High | Record Low |
| Sun Hours |
0 [0%] | 43 hrs (135%) [42%] |
8.4 [96%], 2024 |
0 [0%], 2012 |
| Wet Hours |
0.3 | 16 hrs (73%) [5.5%] |
3.5, 2014 |
, 2009 |
| Cloud Cover |
Overcast |
| Events |
Lying Snow (at 09z): ~3 cm Air Frost |
| Comments |
Ly Snow to 3cm; possible 13, 22 Drizzle |
| Extra Comments |
|
| Issues |
None known |
| Observer Absent? |
Yes - observations may be unreliable |
| Pond Temperature @ Hampstead Heath |
0.0 °C |