Daily Report for 11th May 2011

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 10.2 °C (+1.8) 06:42 9.4 °C (+1.5) 14.7 °C (+6.3), 2016 3.1 °C (-5.2), 2010
Maximum Temperature 17.2 °C (+0.0) 18:00 19.0 °C (+2.2) 22.3 °C (+5.1), 2024 9.2 °C (-8.0), 2010
Mean Temperature 14.3 °C (+0.9) 14.4 °C (+1.9) 16.8 °C, 2015 6.8 °C, 2010
Minimum Humidity 46% 18:30 38% 80%, 2016 37%, 2012
Maximum Humidity 85% 07:45 78% 95%, 2024 72%, 2020
Mean Humidity 64% 57% 88%, 2016 60%, 2020
Minimum Pressure 1021 hPa 20:50 1015 hPa 1021 hPa, 2009 993 hPa, 2017
Maximum Pressure 1024 hPa 04:22 1019 hPa 1033 hPa, 2012 1001 hPa, 2017
Mean Pressure 1022 hPa 1017 hPa 1023 hPa, 2012 995 hPa, 2017
Mean Wind Speed 4.7 mph (+0.0) 5.9 mph (+1.2) 9.9 mph, 2014 2.0 mph, 2019
Maximum Wind Speed 13.0 mph 14.6 mph 18.5 mph, 2013 8.6 mph, 2016
Maximum Gust 17.3 mph 15:08 21.6 mph 30.0 mph, 2020 11.5 mph, 2016
Mean Wind Direction WSW
Rainfall 0.0 mm 4.1 mm (25%) 17.7 mm, 2016
Maximum Hourly Rain n/a 8.1, 2016
Maximum 10-min Rain n/a 4.1, 2016
Maximum Rain Rate n/a 54, 2016
Minimum Dew Point 2.8 °C 23:52 1.7 °C 9.1 °C, 2022 -1.5 °C, 2020
Maximum Dew Point 11.1 °C 08:42 8.9 °C 18.8 °C, 2016 1.4 °C, 2010
Mean Dew Point 7.3 °C 5.4 °C 14.4 °C, 2016 -0.2 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 10.2 °C 06:45 9.6 °C 14.7 °C, 2016 3.1 °C, 2010
Day Maximum (09-21) 17.2 °C 17:30 19.0 °C 22.3 °C, 2024 9.2 °C, 2010
Max 10m Temp Rise 1.0 °C 08:28 0.8 °C 1.0 °C, 2011 0.4 °C, 2010
Max 1hr Temp Rise 3.8 °C 08:49 3.1 °C 4.4 °C, 2018 1.2 °C, 2016
Max 1hr Hum Rise 8% 22:22 8% 24%, 2013 3%, 2016
Max 10m Temp Fall 0.3 °C 11:11 0.4 °C 1.3 °C, 2013 0.3 °C, 2010
Max 1hr Temp Fall 1.2 °C 23:50 1.4 °C 4.0 °C, 2013 1.2 °C, 2010
Max 1hr Hum Fall 10% 09:23 9% 20%, 2018 9%, 2015
Max 10m Wind Speed 7.5 mph 15:21 10.2 mph 13.8 mph, 2020 5.5 mph, 2010
Minimum Feels-like 10.3 °C 06:23 8.4 °C 14.9 °C, 2016 -0.7 °C, 2020
Maximum Feels-like 17.3 °C 17:15 19.4 °C 26.0 °C, 2024 7.9 °C, 2010
Mean Feels-like 14.6 °C 14.5 °C 20.2 °C, 2016 4.9 °C, 2010
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 7.0 °C (-1.8) 9.7 °C (+0.7) 14.5 °C (+5.7), 2017 4.4 °C (-4.5), 2022
Humidity Range 39% 40% 53%, 2012 14%, 2016
Pressure Range 3 hPa 4 hPa 20 hPa, 2019 2 hPa, 2021
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2 [14%]97 hrs (150%) [64%] 11.6 [83%], 2009 0.5 [4%], 2016
Wet Hours 04 hrs (28%) [1.5%] 8, 2016 0, 2009
Cloud Cover Overcast with periods of Mostly Cloudy
Events None
Comments -
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 11th 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

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Webcam Summary of Cloud Conditions

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Wind rose