Daily Report for 29th May 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 12.1 °C (+1.4) 05:35 8.9 °C (-0.1) 14.0 °C (+3.3), 2012 6.8 °C (-3.9), 2022
Maximum Temperature 24.0 °C (+4.8) 14:51 18.3 °C (+0.5) 24.0 °C (+4.8), 2009 12.5 °C (-6.7), 2013
Mean Temperature 17.5 °C (+3.1) 13.3 °C (+0.2) 18.4 °C, 2012 10.8 °C, 2013
Minimum Humidity 39% 20:07 47% 85%, 2018 28%, 2020
Maximum Humidity 95% 07:35 87% 97%, 2014 80%, 2011
Mean Humidity 68% 69% 92%, 2018 55%, 2020
Minimum Pressure 1029 hPa 20:59 1015 hPa 1029 hPa, 2009 1001 hPa, 2013
Maximum Pressure 1033 hPa 06:10 1020 hPa 1033 hPa, 2009 1008 hPa, 2013
Mean Pressure 1031 hPa 1018 hPa 1031 hPa, 2009 1004 hPa, 2013
Mean Wind Speed 5.0 mph (+0.3) 5.9 mph (+1.2) 8.6 mph, 2011 1.8 mph, 2021
Maximum Wind Speed n/a 0.0 mph 17.8, 2011 8.5, 2017
Maximum Gust 23.0 mph 24.0 mph 27.7 mph, 2011 10.9 mph, 2013
Mean Wind Direction n/a
Rainfall 0.0 mm 26.3 mm (61%) 16.3 mm, 2018
Maximum Hourly Rain n/a 8.1, 2018
Maximum 10-min Rain n/a 4, 2017
Maximum Rain Rate n/a 100, 2017
Minimum Dew Point 2.9 °C 20:16 4.0 °C 12.0 °C, 2018 -0.8 °C, 2020
Maximum Dew Point 16.2 °C 10:23 10.2 °C 16.9 °C, 2017 8.0 °C, 2022
Mean Dew Point 10.2 °C 7.1 °C 14.6 °C, 2017 4.6 °C, 2015
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 12.1 °C 9.0 °C 14.0 °C, 2012 6.8 °C, 2022
Day Maximum (09-21) 24.0 °C 18.3 °C 24.0 °C, 2009 12.5 °C, 2013
Max 10m Temp Rise 0.7 °C 10:05 0.7 °C 0.9 °C, 2023 0.3 °C, 2018
Max 1hr Temp Rise 2.8 °C 10:17 2.3 °C 3.1 °C, 2022 1.4 °C, 2018
Max 1hr Hum Rise 12% 21:37 8% 22%, 2019 5%, 2011
Max 10m Temp Fall 0.5 °C 18:54 0.5 °C 0.7 °C, 2017 0.4 °C, 2013
Max 1hr Temp Fall 2.5 °C 19:44 1.6 °C 2.6 °C, 2019 0.8 °C, 2014
Max 1hr Hum Fall 14% 10:05 13% 18%, 2015 4%, 2018
Max 10m Wind Speed n/a 0.0 mph 13.9, 2011 5.8, 2012
Minimum Feels-like n/a 0.0 °C 16.1, 2017 4.7, 2022
Maximum Feels-like n/a 0.0 °C 27.1, 2017 14.5, 2013
Mean Feels-like n/a 0.0 °C 21.6, 2017 11.4, 2013
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 11.9 °C (+3.4) 9.4 °C (+0.7) 12.5 °C (+4.0), 2020 3.7 °C (-4.8), 2010
Humidity Range 56% 40% 56%, 2009 11%, 2018
Pressure Range 4 hPa 5 hPa 10 hPa, 2010 2 hPa, 2012
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 11.6 [79%]168 hrs (96%) [41%] 14.8 [101%], 2020 0 [0%], 2013
Wet Hours 028 hrs (74%) [4%] 4, 2010 0, 2009
Cloud Cover not available
Events None
Comments -
Extra Comments
Issues Tmax corrected as unreliable
Observer Absent? No
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 29th May 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