Daily Report for 6th December 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 7.7 °C (+3.8) 23:18 4.2 °C (+0.2) 12.5 °C (+8.6), 2015 -4.3 °C (-8.2), 2010
Maximum Temperature 12.3 °C (+3.5) 03:43 9.2 °C (+0.2) 14.0 °C (+5.2), 2015 -1.0 °C (-9.8), 2010
Mean Temperature 9.8 °C (+3.6) 6.7 °C (+0.2) 13.2 °C, 2015 -2.4 °C, 2010
Minimum Humidity 66% 14:11 76% 95%, 2010 58%, 2013
Maximum Humidity 96% 08:38 97% 98%, 2010 80%, 2016
Mean Humidity 84% 89% 97%, 2010 68%, 2013
Minimum Pressure 990 hPa 07:38 996 hPa 1025 hPa, 2016 990 hPa, 2009
Maximum Pressure 1004 hPa 23:10 1005 hPa 1033 hPa, 2017 1004 hPa, 2020
Mean Pressure 997 hPa 1001 hPa 1027 hPa, 2013 997 hPa, 2009
Mean Wind Speed 7.8 mph (+2.7) 5.0 mph (-0.1) 9.1 mph, 2015 0.5 mph, 2020
Maximum Wind Speed 13.9 mph 10.0 mph 22.1 mph, 2015 5.5 mph, 2020
Maximum Gust 25.3 mph 08:46 16.0 mph 33.9 mph, 2015 7.6 mph, 2010
Mean Wind Direction SW
Rainfall 7.1 mm 27.6 mm (250%) 7.1 mm, 2009
Maximum Hourly Rain 4.1 mm 09:11 4.1 mm, 2009
Maximum 10-min Rain n/a 08:51 1.3, 2019
Maximum Rain Rate n/a 08:51 26, 2019
Minimum Dew Point 3.9 °C 14:48 2.0 °C 9.2 °C, 2018 -5.2 °C, 2012
Maximum Dew Point 11.3 °C 06:20 8.2 °C 11.6 °C, 2015 -1.3 °C, 2010
Mean Dew Point 7.1 °C 5.0 °C 10.4 °C, 2018 -2.7 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 9.4 °C * 5.2 °C 12.4 °C, 2015 -4.3 °C, 2010
Day Maximum (09-21) * 10.2 °C * 8.6 °C 14.0 °C, 2015 -1.0 °C, 2010
Max 10m Temp Rise 0.4 °C 12:01 0.5 °C 0.5 °C, 2016 0.2 °C, 2010
Max 1hr Temp Rise 0.8 °C 12:46 1.1 °C 1.8 °C, 2016 0.4 °C, 2019
Max 1hr Hum Rise 5% 05:16 5% 9%, 2017 1%, 2016
Max 10m Temp Fall 0.8 °C 09:01 0.4 °C 0.8 °C, 2009 0.2 °C, 2012
Max 1hr Temp Fall 2.0 °C 09:51 1.0 °C 2.0 °C, 2009 0.5 °C, 2015
Max 1hr Hum Fall 22% 12:46 9% 22%, 2009 1%, 2010
Max 10m Wind Speed 12.9 mph 06:40 8.7 mph 16.0 mph, 2015 3.2 mph, 2020
Minimum Feels-like 4.9 °C 23:15 1.2 °C 12.5 °C, 2015 -7.2 °C, 2010
Maximum Feels-like 14.0 °C 06:10 9.9 °C 15.5 °C, 2015 -1.0 °C, 2010
Mean Feels-like 9.7 °C 6.1 °C 14.5 °C, 2015 -2.8 °C, 2010
Air-frost Hrs 0 hrs 0 hrs 24 hrs, 2010 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 4.6 °C (-0.3) 5.1 °C (+0.0) 8.1 °C (+3.2), 2012 1.5 °C (-3.4), 2015
Humidity Range 30% 21% 30%, 2009 3%, 2010
Pressure Range 14 hPa 9 hPa 21 hPa, 2012 2 hPa, 2022
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 3.5 [49%]18 hrs (136%) [40%] 7.2 [100%], 2014 0 [0%], 2010
Wet Hours 5
[Mean rain rate: 1.4 mm/h]
25 hrs (204%) [17%] 10, 2019 0, 2010
Cloud Cover not available
Events None
Comments 05-10 Moderate/Heavy Rain
Extra Comments
Issues 1st - 6th: Rainfall data approx; 10-min totals & rain rates unavailable as 5-min logs; monthly sum is correct.
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 6th 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.
View monthly summary

Daily Graph of Conditions

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose