Daily Report for 29th April 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 2.9 °C (-4.0) 06:33 6.5 °C (+0.5) 11.4 °C (+4.5), 2010 2.9 °C (-4.0), 2009
Maximum Temperature 18.1 °C (+2.2) 17:00 16.0 °C (+1.6) 19.5 °C (+3.6), 2011 7.6 °C (-8.3), 2018
Mean Temperature 10.0 °C (-0.9) 10.8 °C (+1.0) 14.9 °C, 2010 6.7 °C, 2018
Minimum Humidity 41% 17:23 54% 81%, 2018 36%, 2013
Maximum Humidity 96% 08:33 91% 98%, 2012 78%, 2017
Mean Humidity 70% 75% 88%, 2012 52%, 2013
Minimum Pressure 1005 hPa 03:02 1010 hPa 1032 hPa, 2022 998 hPa, 2020
Maximum Pressure 1014 hPa 23:49 1016 hPa 1034 hPa, 2022 1006 hPa, 2020
Mean Pressure 1010 hPa 1013 hPa 1033 hPa, 2022 1003 hPa, 2020
Mean Wind Speed 4.6 mph (-0.3) 4.0 mph (-0.9) 9.8 mph, 2012 2.1 mph, 2014
Maximum Wind Speed n/a 0.0 mph 20.4, 2012 7.8, 2019
Maximum Gust 20.0 mph 19.3 mph 34.6 mph, 2012 11.5 mph, 2019
Mean Wind Direction n/a
Rainfall 0.0 mm 33.0 mm (81%) 16.9 mm, 2012
Maximum Hourly Rain n/a 2.7, 2010
Maximum 10-min Rain n/a 1.4, 2010
Maximum Rain Rate n/a 18, 2015
Minimum Dew Point 0.5 °C 22:00 3.1 °C 6.7 °C, 2014 -3.5 °C, 2015
Maximum Dew Point 8.2 °C 13:01 9.0 °C 13.1 °C, 2012 3.9 °C, 2021
Mean Dew Point 4.2 °C 6.0 °C 8.9 °C, 2010 0.2 °C, 2016
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 2.9 °C 6.8 °C 11.4 °C, 2010 2.9 °C, 2009
Day Maximum (09-21) 18.1 °C 16.0 °C 19.5 °C, 2011 7.6 °C, 2018
Max 10m Temp Rise 0.8 °C 12:57 0.6 °C 1.0 °C, 2017 0.2 °C, 2018
Max 1hr Temp Rise 2.9 °C 13:02 1.7 °C 4.1 °C, 2017 0.4 °C, 2018
Max 1hr Hum Rise 13% 23:15 5% 16%, 2016 3%, 2018
Max 10m Temp Fall 0.5 °C 18:29 0.4 °C 2.0 °C, 2016 0.3 °C, 2012
Max 1hr Temp Fall 2.2 °C 19:04 1.2 °C 3.0 °C, 2016 0.6 °C, 2018
Max 1hr Hum Fall 15% 11:23 7% 25%, 2012 4%, 2018
Max 10m Wind Speed n/a 0.0 mph 14.6, 2012 5.7, 2019
Minimum Feels-like n/a 0.0 °C 11.4, 2010 -0.7, 2021
Maximum Feels-like n/a 0.0 °C 21.5, 2011 6.7, 2018
Mean Feels-like n/a 0.0 °C 15.8, 2010 3.8, 2018
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 15.2 °C (+6.2) 9.5 °C (+1.1) 15.2 °C (+6.2), 2009 1.7 °C (-7.3), 2018
Humidity Range 55% 36% 55%, 2009 11%, 2018
Pressure Range 9 hPa 6 hPa 10 hPa, 2012 2 hPa, 2022
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 10 [75%]179 hrs (115%) [49%] 11 [83%], 2023 0 [0%], 2018
Wet Hours 041 hrs (91%) [5.8%] 13, 2012 0, 2009
Cloud Cover not available
Events None
Comments -
Extra Comments
Issues TMax DATA CORRECTION: -0.5°C from initial
Observer Absent? No
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 29th 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

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Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose