Daily Report for 5th September 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 14.3 °C (+1.8) 23:59 11.4 °C (-1.2) 16.1 °C (+3.6), 2022 7.7 °C (-4.8), 2015
Maximum Temperature 20.4 °C (-0.5) 14:53 21.0 °C (-0.0) 28.7 °C (+7.8), 2023 14.8 °C (-6.1), 2015
Mean Temperature 17.5 °C (+0.6) 16.4 °C (-0.6) 21.5 °C, 2023 11.9 °C, 2015
Minimum Humidity 74% 14:55 57% 85%, 2024 40%, 2013
Maximum Humidity 92% 07:48 89% 97%, 2013 77%, 2012
Mean Humidity 86% 73% 92%, 2024 58%, 2012
Minimum Pressure 1012 hPa 17:31 1014 hPa 1024 hPa, 2012 1008 hPa, 2011
Maximum Pressure 1016 hPa 23:30 1020 hPa 1030 hPa, 2012 1015 hPa, 2011
Mean Pressure 1014 hPa 1017 hPa 1027 hPa, 2012 1011 hPa, 2013
Mean Wind Speed 6.3 mph (+2.4) 3.3 mph (-0.6) 8.0 mph, 2011 1.4 mph, 2021
Maximum Wind Speed 14.1 mph 14:29 10.5 mph 20.7 mph, 2011 6.7 mph, 2014
Maximum Gust 21.9 mph 21:43 16.5 mph 29.9 mph, 2011 8.7 mph, 2014
Mean Wind Direction SW
Rainfall 1.1 mm 10.2 mm (122%) 7.2 mm, 2022
Maximum Hourly Rain 0.9 mm 18:21 5.0 mm, 2022
Maximum 10-min Rain 0.4 mm 17:53 3.1 mm, 2024
Maximum Rain Rate 7 mm/h 17:53 48 mm/h, 2024
Minimum Dew Point 12.4 °C 23:53 8.5 °C 14.1 °C, 2022 4.1 °C, 2019
Maximum Dew Point 16.9 °C 15:20 14.1 °C 19.8 °C, 2016 8.7 °C, 2012
Mean Dew Point 15.2 °C 11.2 °C 16.4 °C, 2016 7.0 °C, 2012
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 16.0 °C * 07:48 11.6 °C 16.1 °C, 2022 9.3 °C, 2015
Day Maximum (09-21) 20.4 °C 14:53 21.0 °C 28.7 °C, 2023 14.8 °C, 2015
Max 10m Temp Rise 0.7 °C 10:05 0.7 °C 1.3 °C, 2009 0.4 °C, 2014
Max 1hr Temp Rise 1.7 °C 10:13 2.2 °C 3.7 °C, 2013 1.0 °C, 2015
Max 1hr Hum Rise 10% 15:48 9% 15%, 2011 6%, 2012
Max 10m Temp Fall 0.7 °C 21:57 0.8 °C 1.2 °C, 2009 0.3 °C, 2010
Max 1hr Temp Fall 2.3 °C 22:43 1.6 °C 2.3 °C, 2013 0.8 °C, 2010
Max 1hr Hum Fall 8% 10:11 8% 17%, 2013 5%, 2016
Max 10m Wind Speed 10.7 mph 14:36 7.9 mph 13.3 mph, 2011 4.3 mph, 2021
Minimum Feels-like 16.8 °C 23:59 12.2 °C 19.9 °C, 2022 7.7 °C, 2015
Maximum Feels-like 24.9 °C 15:20 24.2 °C 35.2 °C, 2023 16.3 °C, 2015
Mean Feels-like 21.6 °C 18.4 °C 26.3 °C, 2023 12.6 °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 6.1 °C (-2.3) 9.5 °C (+1.2) 13.4 °C (+5.0), 2023 6.0 °C (-2.4), 2010
Humidity Range 18% 32% 57%, 2013 12%, 2024
Pressure Range 4 hPa 6 hPa 11 hPa, 2015 2 hPa, 2014
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0.2 [2%]22 hrs (83%) [36%] 12 [99%], 2012 0 [0%], 2016
Wet Hours 2
[Mean rain rate: 0.6 mm/h]		15 hrs (220%) [13%] 7, 2016 0, 2009
Cloud Cover Overcast or Mostly Cloudy
Events None
Comments 15- 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 5th September 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