Daily Report for 23rd April 2015

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 7.5 °C (+1.1) 07:12 5.7 °C (-0.2) 11.7 °C (+5.3), 2019 1.7 °C (-4.7), 2021
Maximum Temperature 16.6 °C (+1.6) 17:49 15.7 °C (+1.6) 26.5 °C (+11.4), 2011 9.8 °C (-5.2), 2016
Mean Temperature 10.9 °C (+1.3) 10.7 °C (+0.7) 18.6 °C, 2011 6.7 °C, 2016
Minimum Humidity 43% 17:31 44% 66%, 2023 23%, 2021
Maximum Humidity 85% 01:08 85% 95%, 2012 68%, 2017
Mean Humidity 65% 64% 84%, 2023 52%, 2011
Minimum Pressure 1015 hPa 22:13 1021 hPa 1029 hPa, 2021 990 hPa, 2012
Maximum Pressure 1025 hPa 00:45 1028 hPa 1031 hPa, 2021 1002 hPa, 2012
Mean Pressure 1020 hPa 1024 hPa 1030 hPa, 2021 996 hPa, 2012
Mean Wind Speed 3.8 mph (-1.1) 4.9 mph (-0.0) 7.8 mph, 2018 1.7 mph, 2011
Maximum Wind Speed 9.2 mph 03:01 12.4 mph 21.5 mph, 2012 7.6 mph, 2010
Maximum Gust 10.7 mph 11:52 17.3 mph 28.5 mph, 2022 10.7 mph, 2015
Mean Wind Direction E
Rainfall 0.0 mm 10.0 mm (31%) 4.1 mm, 2023
Maximum Hourly Rain n/a 3.1, 2023
Maximum 10-min Rain n/a 2.4, 2023
Maximum Rain Rate n/a 30, 2023
Minimum Dew Point 3.3 °C 21:04 0.4 °C 6.7 °C, 2019 -6.3 °C, 2021
Maximum Dew Point 6.2 °C 01:12 7.0 °C 11.6 °C, 2019 3.5 °C, 2010
Mean Dew Point 4.3 °C 3.6 °C 8.2 °C, 2019 0.1 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 7.5 °C 07:12 5.9 °C 11.7 °C, 2019 1.7 °C, 2021
Day Maximum (09-21) 16.6 °C 17:49 15.7 °C 26.5 °C, 2011 9.8 °C, 2016
Max 10m Temp Rise 0.7 °C 11:30 0.6 °C 1.4 °C, 2011 0.5 °C, 2013
Max 1hr Temp Rise 2.3 °C 12:16 2.3 °C 4.9 °C, 2011 1.5 °C, 2022
Max 1hr Hum Rise 9% 21:36 9% 14%, 2012 5%, 2009
Max 10m Temp Fall 0.5 °C 19:35 0.6 °C 1.2 °C, 2009 0.4 °C, 2013
Max 1hr Temp Fall 2.5 °C 20:21 2.0 °C 2.7 °C, 2009 1.3 °C, 2018
Max 1hr Hum Fall 9% 12:26 13% 20%, 2021 5%, 2017
Max 10m Wind Speed 7.7 mph 03:03 9.5 mph 12.3 mph, 2018 7.4 mph, 2020
Minimum Feels-like 4.7 °C 07:11 3.3 °C 11.8 °C, 2019 -0.9 °C, 2016
Maximum Feels-like 16.6 °C 17:38 15.8 °C 26.9 °C, 2011 9.5 °C, 2016
Mean Feels-like 10.3 °C 10.0 °C 19.0 °C, 2011 4.9 °C, 2016
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 9.1 °C (+0.4) 10.1 °C (+1.8) 16.4 °C (+7.7), 2011 3.9 °C (-4.8), 2012
Humidity Range 42% 41% 69%, 2021 25%, 2017
Pressure Range 10 hPa 7 hPa 12 hPa, 2012 2 hPa, 2010
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 8 [62%]165 hrs (136%) [58%] 13 [100%], 2010 0 [0%], 2019
Wet Hours 018 hrs (50%) [3.2%] 7, 2012 0, 2009
Cloud Cover am: Overcast transitioned to Mostly Sunny
pm: Sunny
Events None
Comments data is awaiting quality control from site operator
Extra Comments
Issues 00-07 lossy wind data
Observer Absent? No
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 23rd April 2015.
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