Daily Report for 22nd April 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 7.0 °C (+0.7) 06:40 6.8 °C (+1.0) 12.1 °C (+5.8), 2018 2.3 °C (-4.0), 2010
Maximum Temperature 19.7 °C (+4.8) 16:02 16.0 °C (+1.9) 25.6 °C (+10.7), 2011 9.4 °C (-5.5), 2024
Mean Temperature 12.9 °C (+2.8) 10.8 °C (+1.5) 18.0 °C, 2011 7.0 °C, 2024
Minimum Humidity 33% 17:04 58% 67%, 2024 29%, 2019
Maximum Humidity 82% 07:40 92% 97%, 2023 75%, 2011
Mean Humidity 59% 77% 82%, 2014 50%, 2011
Minimum Pressure 1023 hPa 19:55 1012 hPa 1027 hPa, 2024 1002 hPa, 2019
Maximum Pressure 1028 hPa 05:04 1017 hPa 1033 hPa, 2015 1004 hPa, 2012
Mean Pressure 1026 hPa 1015 hPa 1030 hPa, 2015 1004 hPa, 2012
Mean Wind Speed 4.2 mph (-0.7) 3.9 mph (-1.0) 7.1 mph, 2022 2.7 mph, 2011
Maximum Wind Speed n/a 0.0 mph 18.5, 2012 7.7, 2024
Maximum Gust 17.0 mph 18.5 mph 25.1 mph, 2012 11.5 mph, 2017
Mean Wind Direction n/a
Rainfall 0.0 mm 27.4 mm (89%) 5.5 mm, 2016
Maximum Hourly Rain n/a 2.6, 2018
Maximum 10-min Rain n/a 1.3, 2018
Maximum Rain Rate n/a 13, 2018
Minimum Dew Point 2.2 °C 19:18 3.7 °C 6.7 °C, 2014 -3.6 °C, 2010
Maximum Dew Point 6.2 °C 00:06 9.4 °C 14.6 °C, 2018 2.4 °C, 2010
Mean Dew Point 4.7 °C 6.6 °C 11.8 °C, 2018 0.2 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 7.0 °C 7.0 °C 13.2 °C, 2018 2.3 °C, 2010
Day Maximum (09-21) 19.7 °C 15.9 °C 25.6 °C, 2011 9.4 °C, 2024
Max 10m Temp Rise 0.8 °C 11:31 0.5 °C 1.0 °C, 2019 0.2 °C, 2016
Max 1hr Temp Rise 3.2 °C 13:37 1.4 °C 3.6 °C, 2019 0.9 °C, 2016
Max 1hr Hum Rise 10% 21:01 4% 28%, 2012 5%, 2024
Max 10m Temp Fall 0.8 °C 20:42 0.3 °C 1.1 °C, 2012 0.3 °C, 2013
Max 1hr Temp Fall 2.0 °C 21:26 0.9 °C 4.3 °C, 2012 0.9 °C, 2024
Max 1hr Hum Fall 10% 12:21 5% 17%, 2014 3%, 2016
Max 10m Wind Speed n/a 0.0 mph 13.6, 2018 5.8, 2024
Minimum Feels-like n/a 0.0 °C 12.1, 2018 -0.4, 2021
Maximum Feels-like n/a 0.0 °C 25.8, 2018 9.4, 2024
Mean Feels-like n/a 0.0 °C 20.1, 2018 5.5, 2024
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 12.7 °C (+4.1) 9.1 °C (+0.9) 16.4 °C (+7.8), 2019 5.2 °C (-3.4), 2016
Humidity Range 49% 34% 50%, 2012 24%, 2024
Pressure Range 5 hPa 6 hPa 13 hPa, 2019 1 hPa, 2012
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 12.5 [97%]126 hrs (109%) [47%] 13 [101%], 2020 0 [0%], 2016
Wet Hours 033 hrs (98%) [6.3%] 10, 2016 0, 2009
Cloud Cover not available
Events Maximum possible sunshine
Comments -
Extra Comments
Issues TMax DATA CORRECTION: -1.0°C from initial
Observer Absent? No
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 22nd April 2009.
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

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose