Daily Report for 31st July 2019

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 16.4 °C (+1.8) 05:55 15.1 °C (+0.9) 19.3 °C (+4.7), 2022 8.5 °C (-6.1), 2015
Maximum Temperature 22.9 °C (-0.4) 17:50 24.5 °C (+1.4) 36.2 °C (+12.9), 2020 18.8 °C (-4.5), 2023
Mean Temperature 18.8 °C (+0.7) 19.8 °C (+1.1) 25.6 °C, 2020 15.9 °C, 2015
Minimum Humidity 46% 21:25 50% 76%, 2023 29%, 2020
Maximum Humidity 87% 03:59 86% 96%, 2023 73%, 2016
Mean Humidity 71% 69% 88%, 2023 57%, 2020
Minimum Pressure 1008 hPa 23:47 1014 hPa 1016 hPa, 2022 1002 hPa, 2023
Maximum Pressure 1016 hPa 23:50 1019 hPa 1023 hPa, 2009 1011 hPa, 2023
Mean Pressure 1013 hPa 1017 hPa 1019 hPa, 2009 1006 hPa, 2023
Mean Wind Speed 7.3 mph (+3.0) 4.2 mph (-0.1) 7.3 mph, 2019 2.0 mph, 2024
Maximum Wind Speed 15.8 mph 08:50 12.0 mph 16.6 mph, 2023 8.5 mph, 2024
Maximum Gust 25.3 mph 17:10 19.1 mph 28.8 mph, 2023 12.3 mph, 2015
Mean Wind Direction WSW
Rainfall 0.0 mm 43.5 mm (95%) 6.0 mm, 2023
Maximum Hourly Rain n/a 4.2, 2018
Maximum 10-min Rain n/a 2, 2018
Maximum Rain Rate n/a 53, 2018
Minimum Dew Point 8.2 °C 21:27 11.0 °C 16.0 °C, 2022 4.4 °C, 2015
Maximum Dew Point 14.5 °C 23:40 15.7 °C 19.0 °C, 2022 10.7 °C, 2009
Mean Dew Point 13.1 °C 13.5 °C 17.5 °C, 2022 6.8 °C, 2015
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 16.4 °C 06:03 15.2 °C 19.7 °C, 2022 8.5 °C, 2015
Day Maximum (09-21) 22.9 °C 17:51 24.4 °C 36.2 °C, 2020 18.8 °C, 2023
Max 10m Temp Rise 0.6 °C 15:38 0.6 °C 0.8 °C, 2009 0.4 °C, 2013
Max 1hr Temp Rise 1.8 °C 11:41 2.2 °C 3.8 °C, 2015 1.1 °C, 2023
Max 1hr Hum Rise 15% 22:58 10% 15%, 2019 4%, 2016
Max 10m Temp Fall 0.5 °C 18:35 0.5 °C 0.9 °C, 2020 0.3 °C, 2010
Max 1hr Temp Fall 1.1 °C 20:05 1.8 °C 3.6 °C, 2020 1.1 °C, 2013
Max 1hr Hum Fall 12% 17:26 10% 15%, 2015 6%, 2022
Max 10m Wind Speed 12.2 mph 08:52 8.7 mph 13.1 mph, 2022 3.7 mph, 2009
Minimum Feels-like 19.8 °C 05:24 17.6 °C 23.9 °C, 2022 8.5 °C, 2015
Maximum Feels-like 24.8 °C 17:44 28.3 °C 41.3 °C, 2020 21.7 °C, 2015
Mean Feels-like 21.7 °C 23.0 °C 29.7 °C, 2020 16.1 °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 6.5 °C (-2.1) 9.3 °C (+0.5) 19.6 °C (+11.0), 2020 3.0 °C (-5.6), 2023
Humidity Range 41% 37% 54%, 2020 20%, 2023
Pressure Range 8 hPa 5 hPa 8 hPa, 2023 2 hPa, 2010
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2.5 [18%]190 hrs (98%) [42%] 12 [85%], 2011 0.1 [1%], 2012
Wet Hours 043 hrs (127%) [5.8%] 9, 2025 0, 2009
Cloud Cover am: Overcast
pm: Mostly Cloudy
Events None
Comments -
Extra Comments
Issues ~30m data loss ~18 due to server cpu peg
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 21.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 31st July 2019.
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

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Webcam Summary of Cloud Conditions

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