Daily Report for 24th May 2011

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 8.2 °C (-1.8) 05:25 9.4 °C (+0.7) 14.4 °C (+4.4), 2010 5.4 °C (-4.6), 2013
Maximum Temperature 19.0 °C (+0.4) 16:35 18.7 °C (+1.3) 28.8 °C (+10.2), 2010 8.9 °C (-9.7), 2013
Mean Temperature 13.8 °C (-0.7) 14.3 °C (+1.0) 20.9 °C, 2010 6.8 °C, 2013
Minimum Humidity 34% 18:30 40% 73%, 2013 32%, 2010
Maximum Humidity 76% 05:45 79% 94%, 2018 69%, 2010
Mean Humidity 51% 58% 83%, 2021 51%, 2011
Minimum Pressure 1020 hPa 00:34 1016 hPa 1028 hPa, 2020 1002 hPa, 2022
Maximum Pressure 1029 hPa 23:03 1021 hPa 1034 hPa, 2020 1010 hPa, 2021
Mean Pressure 1024 hPa 1018 hPa 1031 hPa, 2020 1004 hPa, 2021
Mean Wind Speed 6.6 mph (+1.9) 6.0 mph (+1.3) 7.3 mph, 2025 1.2 mph, 2017
Maximum Wind Speed 15.0 mph 14.5 mph 18.9 mph, 2022 7.7 mph, 2017
Maximum Gust 21.9 mph 12:13 21.2 mph 26.6 mph, 2013 10.5 mph, 2017
Mean Wind Direction W
Rainfall 0.0 mm 8.3 mm (23%) 9.3 mm, 2013
Maximum Hourly Rain n/a 5.2, 2025
Maximum 10-min Rain n/a 2, 2019
Maximum Rain Rate n/a 26, 2019
Minimum Dew Point 0.7 °C 22:40 2.8 °C 12.6 °C, 2012 0.7 °C, 2011
Maximum Dew Point 5.1 °C 00:02 8.8 °C 17.6 °C, 2012 5.1 °C, 2011
Mean Dew Point 3.1 °C 5.8 °C 15.5 °C, 2012 3.1 °C, 2011
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 8.2 °C 05:25 9.6 °C 15.2 °C, 2010 5.4 °C, 2013
Day Maximum (09-21) 19.0 °C 16:30 18.7 °C 28.8 °C, 2010 8.9 °C, 2013
Max 10m Temp Rise 0.5 °C 11:17 0.7 °C 0.9 °C, 2009 0.4 °C, 2010
Max 1hr Temp Rise 1.9 °C 08:55 2.9 °C 3.9 °C, 2009 1.5 °C, 2025
Max 1hr Hum Rise 5% 23:27 8% 20%, 2019 5%, 2009
Max 10m Temp Fall 0.9 °C 20:16 0.5 °C 2.3 °C, 2022 0.3 °C, 2025
Max 1hr Temp Fall 4.0 °C 20:25 1.6 °C 4.0 °C, 2010 1.2 °C, 2025
Max 1hr Hum Fall 9% 09:13 10% 22%, 2016 6%, 2024
Max 10m Wind Speed 10.1 mph 12:28 10.1 mph 13.5 mph, 2021 5.1 mph, 2017
Minimum Feels-like 5.4 °C 05:19 8.5 °C 16.9 °C, 2012 1.5 °C, 2013
Maximum Feels-like 19.0 °C 16:26 19.1 °C 31.4 °C, 2012 8.2 °C, 2013
Mean Feels-like 13.3 °C 14.5 °C 24.5 °C, 2012 4.4 °C, 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 10.8 °C (+2.2) 9.3 °C (+0.5) 14.8 °C (+6.2), 2009 3.5 °C (-5.1), 2013
Humidity Range 42% 38% 43%, 2016 18%, 2013
Pressure Range 9 hPa 5 hPa 14 hPa, 2013 2 hPa, 2012
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 13 [90%]181 hrs (125%) [54%] 14.5 [100%], 2009 0.1 [1%], 2013
Wet Hours 06.3 hrs (20%) [1.1%] 8, 2013 0, 2009
Cloud Cover Sunny or Mostly Sunny
Events None
Comments -
Extra Comments
Issues Data loss (1420-1850) - Tmax, Hmin, Sun and cloud cover are estimates
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 24th May 2011.
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.
View monthly summary

Daily Graph of Conditions

day graph

Webcam Summary of Cloud Conditions

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Wind rose