Daily Report for 16th December 2021

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 9.8 °C (+6.3) 22:10 5.0 °C (+1.3) 13.2 °C (+9.7), 2015 -3.9 °C (-7.4), 2022
Maximum Temperature 11.8 °C (+3.9) 00:04 9.2 °C (+0.7) 15.0 °C (+7.1), 2015 2.1 °C (-5.8), 2022
Mean Temperature 10.8 °C (+5.1) 7.2 °C (+1.0) 13.9 °C, 2015 -1.3 °C, 2022
Minimum Humidity 76% 14:39 78% 88%, 2013 75%, 2017
Maximum Humidity 84% 08:01 92% 98%, 2009 81%, 2016
Mean Humidity 80% 85% 94%, 2013 80%, 2016
Minimum Pressure 1036 hPa 00:00 1006 hPa 1038 hPa, 2023 980 hPa, 2011
Maximum Pressure 1042 hPa 23:50 1017 hPa 1042 hPa, 2021 1001 hPa, 2012
Mean Pressure 1039 hPa 1011 hPa 1039 hPa, 2023 992 hPa, 2011
Mean Wind Speed 0.1 mph (-5.0) 6.0 mph (+0.9) 8.1 mph, 2013 0.1 mph, 2021
Maximum Wind Speed 4.3 mph 19:45 13.7 mph 19.7 mph, 2013 4.3 mph, 2021
Maximum Gust 6.8 mph 19:44 22.7 mph 29.9 mph, 2013 6.3 mph, 2016
Mean Wind Direction W
Rainfall 0.0 mm 25.4 mm (86%) 8.8 mm, 2013
Maximum Hourly Rain n/a 4.6, 2018
Maximum 10-min Rain n/a 2.2, 2018
Maximum Rain Rate n/a 26, 2018
Minimum Dew Point 6.5 °C 20:58 2.7 °C 11.1 °C, 2015 -5.6 °C, 2010
Maximum Dew Point 8.5 °C 02:06 7.3 °C 12.7 °C, 2015 -0.1 °C, 2022
Mean Dew Point 7.6 °C 4.9 °C 12.0 °C, 2015 -2.6 °C, 2022
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 10.6 °C * 07:58 5.5 °C 12.6 °C, 2015 -2.8 °C, 2022
Day Maximum (09-21) * 11.4 °C * 13:14 9.0 °C 15.0 °C, 2015 2.1 °C, 2022
Max 10m Temp Rise 0.2 °C 10:29 0.3 °C 0.5 °C, 2009 0.1 °C, 2016
Max 1hr Temp Rise 0.4 °C 10:59 1.1 °C 1.6 °C, 2018 0.4 °C, 2016
Max 1hr Hum Rise 3% 16:35 5% 8%, 2017 1%, 2016
Max 10m Temp Fall 0.2 °C 19:14 0.4 °C 0.8 °C, 2009 0.2 °C, 2014
Max 1hr Temp Fall 0.4 °C 16:20 1.0 °C 2.4 °C, 2010 0.4 °C, 2021
Max 1hr Hum Fall 5% 10:56 5% 14%, 2010 2%, 2009
Max 10m Wind Speed 1.9 mph 14:34 10.7 mph 15.0 mph, 2013 1.9 mph, 2021
Minimum Feels-like 9.8 °C 20:22 1.3 °C 15.4 °C, 2015 -7.4 °C, 2010
Maximum Feels-like 12.4 °C 00:00 9.1 °C 17.6 °C, 2015 0.6 °C, 2011
Mean Feels-like 11.1 °C 5.4 °C 16.2 °C, 2015 -2.6 °C, 2022
Air-frost Hrs 0 hrs 0 hrs 19 hrs, 2022 0 hrs, 2011
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 2.0 °C (-2.3) 4.2 °C (-0.5) 8.7 °C (+4.4), 2010 1.8 °C (-2.5), 2015
Humidity Range 8% 14% 20%, 2011 3%, 2016
Pressure Range 6 hPa 11 hPa 26 hPa, 2010 3 hPa, 2023
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0 [0%]28 hrs (82%) [24%] 7 [100%], 2022 0 [0%], 2010
Wet Hours 029 hrs (91%) [7.6%] 11, 2009 0, 2016
Cloud Cover Overcast
Events None
Comments -
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 6.5 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 16th December 2021.
Times of extremes are computed using the midpoint of the longest continuous period at that extreme value.
Cumulative anomalies are reported according to the expected value for the month-to-date rather than month-end.
Sun hrs are derived based on analysis of webcam observations, but may use data from our closest site, Heathrow, when needed.
Wet hrs are dervied algorithmically from rainfall data, though may be adjusted manually.
Rainfall totals may be manually adjusted after the fact to correct delayed or erroneous data.
Cloud cover and Events are manually reported, often with multi-week delays.
Data is generally reliable and accurate but should always be viewed with some quantity of salt to hand.
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