Daily Report for 17th August 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 16.2 °C (+2.1) 02:35 13.4 °C (-0.9) 18.1 °C (+4.0), 2012 10.8 °C (-3.3), 2018
Maximum Temperature 24.1 °C (+1.7) 14:26 21.5 °C (-1.4) 27.6 °C (+5.2), 2012 18.2 °C (-4.2), 2021
Mean Temperature 19.6 °C (+1.9) 17.4 °C (-1.2) 22.2 °C, 2012 15.4 °C, 2021
Minimum Humidity 47% 18:02 50% 76%, 2021 33%, 2012
Maximum Humidity 85% 07:45 81% 98%, 2020 76%, 2012
Mean Humidity 69% 66% 90%, 2022 58%, 2012
Minimum Pressure 1010 hPa 00:05 1013 hPa 1019 hPa, 2021 1004 hPa, 2019
Maximum Pressure 1015 hPa 00:19 1019 hPa 1023 hPa, 2023 1006 hPa, 2019
Mean Pressure 1012 hPa 1016 hPa 1021 hPa, 2023 1005 hPa, 2019
Mean Wind Speed 6.2 mph (+2.2) 4.2 mph (+0.2) 7.6 mph, 2014 1.9 mph, 2015
Maximum Wind Speed 14.3 mph 12:35 12.2 mph 17.6 mph, 2014 9.0 mph, 2015
Maximum Gust 22.0 mph 12:51 18.6 mph 26.8 mph, 2013 12.1 mph, 2011
Mean Wind Direction SW
Rainfall 5.3 mm 56.1 mm (189%) 35.8 mm, 2022
Maximum Hourly Rain 4.1 mm 02:03 23.1 mm, 2022
Maximum 10-min Rain 1.5 mm 01:25 9.9 mm, 2022
Maximum Rain Rate 18 mm/h 02:01 90 mm/h, 2022
Minimum Dew Point 10.0 °C 00:10 7.8 °C 15.4 °C, 2022 4.1 °C, 2014
Maximum Dew Point 16.7 °C 11:29 13.2 °C 19.2 °C, 2022 11.3 °C, 2015
Mean Dew Point 13.5 °C 10.6 °C 16.9 °C, 2022 8.0 °C, 2015
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 16.2 °C 02:35 13.6 °C 18.1 °C, 2012 10.8 °C, 2018
Day Maximum (09-21) 24.1 °C 14:26 21.5 °C 27.6 °C, 2012 18.2 °C, 2021
Max 10m Temp Rise 0.5 °C 12:33 0.6 °C 1.0 °C, 2009 0.3 °C, 2010
Max 1hr Temp Rise 1.8 °C 13:21 2.1 °C 3.1 °C, 2018 0.9 °C, 2010
Max 1hr Hum Rise 13% 02:11 7% 22%, 2022 3%, 2015
Max 10m Temp Fall 0.4 °C 18:50 0.5 °C 1.8 °C, 2022 0.3 °C, 2010
Max 1hr Temp Fall 1.7 °C 20:38 1.7 °C 5.0 °C, 2022 0.7 °C, 2021
Max 1hr Hum Fall 16% 13:25 9% 27%, 2014 4%, 2010
Max 10m Wind Speed 11.3 mph 13:16 9.0 mph 13.1 mph, 2014 5.8 mph, 2015
Minimum Feels-like 18.5 °C 02:06 14.4 °C 20.6 °C, 2012 11.8 °C, 2018
Maximum Feels-like 27.3 °C 15:21 23.6 °C 30.9 °C, 2022 20.6 °C, 2015
Mean Feels-like 22.8 °C 19.1 °C 25.0 °C, 2012 17.2 °C, 2015
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 7.9 °C (-0.4) 8.0 °C (-0.5) 12.0 °C (+3.7), 2016 5.2 °C (-3.1), 2010
Humidity Range 38% 31% 49%, 2016 13%, 2021
Pressure Range 5 hPa 6 hPa 10 hPa, 2013 2 hPa, 2011
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 5 [38%]92 hrs (88%) [40%] 12 [91%], 2016 0 [0%], 2021
Wet Hours 2.5
[Mean rain rate: 2.1 mm/h]
26 hrs (122%) [6.3%] 5, 2022 0, 2009
Cloud Cover am: Overcast
pm: Partly Cloudy
Events None
Comments o.night Rain
Extra Comments
Issues Rn data from N16
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 17th August 2017.
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

day graph

Webcam Summary of Cloud Conditions

daycamsumLarge resolution version

Wind rose