Daily Report for 14th December 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 0.5 °C (-3.1) 05:24 4.0 °C (+0.2) 9.8 °C (+6.2), 2021 -2.8 °C (-6.4), 2022
Maximum Temperature 4.7 °C (-3.4) 14:54 8.8 °C (+0.2) 14.6 °C (+6.5), 2016 0.4 °C (-7.7), 2022
Mean Temperature 2.8 °C (-3.2) 6.5 °C (+0.2) 11.1 °C, 2021 -1.2 °C, 2022
Minimum Humidity 89% 16:01 82% 90%, 2023 61%, 2019
Maximum Humidity 98% 09:42 97% 98%, 2009 80%, 2011
Mean Humidity 95% 91% 95%, 2009 75%, 2011
Minimum Pressure 1019 hPa 21:07 1008 hPa 1027 hPa, 2010 975 hPa, 2012
Maximum Pressure 1025 hPa 03:22 1016 hPa 1037 hPa, 2010 993 hPa, 2017
Mean Pressure 1022 hPa 1012 hPa 1032 hPa, 2010 985 hPa, 2012
Mean Wind Speed 1.5 mph (-3.6) 4.5 mph (-0.6) 8.5 mph, 2019 1.5 mph, 2009
Maximum Wind Speed 4.3 mph 10.1 mph 23.4 mph, 2019 4.3 mph, 2009
Maximum Gust 6.2 mph 00:16 15.2 mph 42.6 mph, 2019 6.2 mph, 2009
Mean Wind Direction NE
Rainfall 0.3 mm 33.5 mm (130%) 11.0 mm, 2019
Maximum Hourly Rain 0.3 mm 19:38 5.9 mm, 2019
Maximum 10-min Rain n/a 19:38 2.6, 2019
Maximum Rain Rate n/a 26, 2019
Minimum Dew Point -0.2 °C 04:07 2.6 °C 8.1 °C, 2021 -4.4 °C, 2022
Maximum Dew Point 4.1 °C 13:10 7.8 °C 10.3 °C, 2020 -0.7 °C, 2022
Mean Dew Point 2.0 °C 5.1 °C 9.3 °C, 2021 -2.8 °C, 2022
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 0.5 °C 5.0 °C 9.7 °C, 2021 -2.3 °C, 2022
Day Maximum (09-21) 4.7 °C 8.5 °C 14.6 °C, 2016 0.4 °C, 2022
Max 10m Temp Rise n/a 16:21 0.4 °C 1.2, 2022 0.2, 2010
Max 1hr Temp Rise n/a 17:11 1.0 °C 2.6, 2016 0.6, 2010
Max 1hr Hum Rise n/a 04:39 4% 9, 2013 2, 2015
Max 10m Temp Fall n/a 16:11 0.3 °C 0.5, 2019 0.1, 2014
Max 1hr Temp Fall n/a 16:11 0.9 °C 1.7, 2020 0.2, 2014
Max 1hr Hum Fall n/a 14:03 6% 13, 2019 2, 2015
Max 10m Wind Speed 3.4 mph 02:28 7.9 mph 19.3 mph, 2019 3.4 mph, 2009
Minimum Feels-like -0.9 °C 02:09 1.4 °C 7.1 °C, 2021 -9.3 °C, 2022
Maximum Feels-like 4.7 °C 14:36 9.4 °C 15.7 °C, 2016 -0.7 °C, 2022
Mean Feels-like 2.6 °C 5.8 °C 11.8 °C, 2021 -5.6 °C, 2022
Air-frost Hrs 0 hrs 0 hrs 22 hrs, 2022 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 4.2 °C (-0.3) 4.7 °C (-0.1) 8.8 °C (+4.3), 2012 1.9 °C (-2.6), 2011
Humidity Range 9% 15% 31%, 2019 7%, 2021
Pressure Range 6 hPa 8 hPa 24 hPa, 2012 3 hPa, 2016
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 3 [43%]38 hrs (126%) [38%] 5 [71%], 2016 0 [0%], 2012
Wet Hours 1.533 hrs (116%) [9.7%] 7, 2020 0, 2016
Cloud Cover not available
Events None
Comments 18-20 SLight Rain
Extra Comments
Issues None known
Observer Absent? No
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 14th December 2009.
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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Daily Graph of Conditions

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose