Daily Report for 20th August 2016

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 15.0 °C (+1.1) 06:16 14.2 °C (-0.0) 18.4 °C (+4.5), 2018 8.6 °C (-5.3), 2014
Maximum Temperature 20.1 °C (-2.2) 14:56 22.4 °C (-0.3) 24.9 °C (+2.6), 2012 18.9 °C (-3.4), 2014
Mean Temperature 17.0 °C (-0.5) 18.2 °C (-0.2) 21.7 °C, 2018 13.8 °C, 2014
Minimum Humidity 50% 14:38 47% 72%, 2010 34%, 2013
Maximum Humidity 85% 03:37 84% 94%, 2020 80%, 2013
Mean Humidity 76% 67% 84%, 2015 56%, 2013
Minimum Pressure 1004 hPa 11:19 1015 hPa 1026 hPa, 2013 1000 hPa, 2020
Maximum Pressure 1009 hPa 23:46 1020 hPa 1028 hPa, 2013 1005 hPa, 2020
Mean Pressure 1006 hPa 1016 hPa 1027 hPa, 2013 1004 hPa, 2020
Mean Wind Speed 13.5 mph (+9.5) 6.8 mph (+2.8) 13.5 mph, 2016 2.0 mph, 2021
Maximum Wind Speed 26.4 mph 16:46 17.5 mph 26.4 mph, 2016 7.8 mph, 2013
Maximum Gust 45.2 mph 15:21 26.7 mph 45.2 mph, 2016 10.2 mph, 2013
Mean Wind Direction SW
Rainfall 1.6 mm 15.0 mm (43%) 4.6 mm, 2011
Maximum Hourly Rain 0.6 mm 10:08 3.6 mm, 2011
Maximum 10-min Rain 0.6 mm 18:54 1.4 mm, 2011
Maximum Rain Rate 11 mm/h 18:48 15 mm/h, 2011
Minimum Dew Point 9.3 °C 15:05 8.8 °C 15.6 °C, 2018 2.6 °C, 2014
Maximum Dew Point 14.6 °C 10:53 14.2 °C 19.2 °C, 2020 8.6 °C, 2014
Mean Dew Point 12.5 °C 11.4 °C 16.6 °C, 2018 5.3 °C, 2014
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 15.0 °C 06:16 14.4 °C 18.4 °C, 2018 8.6 °C, 2014
Day Maximum (09-21) 20.1 °C 14:56 22.4 °C 24.9 °C, 2012 18.9 °C, 2014
Max 10m Temp Rise 0.6 °C 10:44 0.6 °C 0.7 °C, 2013 0.4 °C, 2010
Max 1hr Temp Rise 1.6 °C 11:16 1.9 °C 2.9 °C, 2013 1.2 °C, 2010
Max 1hr Hum Rise 11% 16:24 8% 12%, 2011 4%, 2010
Max 10m Temp Fall 0.8 °C 18:54 0.5 °C 0.8 °C, 2016 0.2 °C, 2010
Max 1hr Temp Fall 1.7 °C 19:21 1.6 °C 3.2 °C, 2013 0.4 °C, 2010
Max 1hr Hum Fall 12% 13:04 11% 15%, 2013 2%, 2010
Max 10m Wind Speed 21.9 mph 15:09 13.2 mph 21.9 mph, 2016 6.3 mph, 2013
Minimum Feels-like 17.5 °C 05:57 15.9 °C 22.7 °C, 2018 6.9 °C, 2014
Maximum Feels-like 22.3 °C 12:03 24.7 °C 31.1 °C, 2018 18.9 °C, 2014
Mean Feels-like 19.5 °C 20.3 °C 26.7 °C, 2018 13.8 °C, 2014
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.1 °C (-3.3) 8.2 °C (-0.3) 13.1 °C (+4.7), 2013 4.2 °C (-4.2), 2010
Humidity Range 35% 37% 50%, 2020 16%, 2010
Pressure Range 5 hPa 4 hPa 8 hPa, 2009 2 hPa, 2025
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2 [15%]121 hrs (99%) [45%] 11 [85%], 2020 0.2 [2%], 2015
Wet Hours 2
[Mean rain rate: 0.8 mm/h]		22 hrs (91%) [4.6%] 4, 2017 0, 2009
Cloud Cover Mostly Cloudy with periods of Partly Cloudy
Events None
Comments Showers
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 20th August 2016.
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

day graph

Webcam Summary of Cloud Conditions

daycamsumLarge resolution version

Wind rose