Daily Report for 11th May 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 6.6 °C (-1.8) 05:28 7.4 °C (-0.4) 14.7 °C (+6.3), 2016 3.1 °C (-5.2), 2010
Maximum Temperature 21.1 °C (+3.9) 14:33 15.2 °C (-1.6) 22.3 °C (+5.1), 2024 9.2 °C (-8.0), 2010
Mean Temperature 14.1 °C (+1.1) 11.1 °C (-1.0) 16.8 °C, 2015 6.8 °C, 2010
Minimum Humidity 43% 13:45 54% 80%, 2016 37%, 2012
Maximum Humidity 82% 06:57 81% 95%, 2024 72%, 2020
Mean Humidity 62% 68% 88%, 2016 60%, 2020
Minimum Pressure 993 hPa 17:50 1012 hPa 1021 hPa, 2009 993 hPa, 2017
Maximum Pressure 1001 hPa 00:10 1021 hPa 1033 hPa, 2012 1001 hPa, 2017
Mean Pressure 995 hPa 1016 hPa 1023 hPa, 2012 995 hPa, 2017
Mean Wind Speed 2.5 mph (-2.2) 4.3 mph (-0.4) 9.9 mph, 2014 2.0 mph, 2019
Maximum Wind Speed 9.9 mph 15:57 10.9 mph 18.5 mph, 2013 8.6 mph, 2016
Maximum Gust 14.7 mph 13:24 17.3 mph 30.0 mph, 2020 11.5 mph, 2016
Mean Wind Direction ESE
Rainfall 1.0 mm 8.4 mm (51%) 17.7 mm, 2016
Maximum Hourly Rain 1.0 mm 23:45 8.1 mm, 2016
Maximum 10-min Rain 0.4 mm 23:26 4.1 mm, 2016
Maximum Rain Rate 2.0 mm/h 23:26 54 mm/h, 2016
Minimum Dew Point 3.0 °C 05:03 3.1 °C 9.1 °C, 2022 -1.5 °C, 2020
Maximum Dew Point 9.4 °C 11:07 7.4 °C 18.8 °C, 2016 1.4 °C, 2010
Mean Dew Point 6.5 °C 5.2 °C 14.4 °C, 2016 -0.2 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 6.6 °C 05:28 7.5 °C 14.7 °C, 2016 3.1 °C, 2010
Day Maximum (09-21) 21.1 °C 14:33 15.2 °C 22.3 °C, 2024 9.2 °C, 2010
Max 10m Temp Rise 0.8 °C 07:30 0.6 °C 1.0 °C, 2011 0.4 °C, 2010
Max 1hr Temp Rise 3.1 °C 11:28 1.8 °C 4.4 °C, 2018 1.2 °C, 2016
Max 1hr Hum Rise 14% 23:24 9% 24%, 2013 3%, 2016
Max 10m Temp Fall 0.4 °C 20:41 0.4 °C 1.3 °C, 2013 0.3 °C, 2010
Max 1hr Temp Fall 1.9 °C 21:19 1.4 °C 4.0 °C, 2013 1.2 °C, 2010
Max 1hr Hum Fall 16% 11:54 10% 20%, 2018 9%, 2015
Max 10m Wind Speed 7.0 mph 16:44 8.2 mph 13.8 mph, 2020 5.5 mph, 2010
Minimum Feels-like 5.4 °C 06:33 5.0 °C 14.9 °C, 2016 -0.7 °C, 2020
Maximum Feels-like 21.8 °C 14:29 15.4 °C 26.0 °C, 2024 7.9 °C, 2010
Mean Feels-like 14.2 °C 10.4 °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 14.5 °C (+5.7) 7.8 °C (-1.1) 14.5 °C (+5.7), 2017 4.4 °C (-4.5), 2022
Humidity Range 39% 26% 53%, 2012 14%, 2016
Pressure Range 8 hPa 8 hPa 20 hPa, 2019 2 hPa, 2021
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 3.3 [24%]43 hrs (66%) [29%] 11.6 [83%], 2009 0.5 [4%], 2016
Wet Hours 2
[Mean rain rate: 0.5 mm/h]
7 hrs (49%) [2.7%] 8, 2016 0, 2009
Cloud Cover Hazy with periods of Mostly Sunny
Events None
Comments 22- Rain
Extra Comments
Issues Rn data from casa
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 2017.
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

daycamsumLarge resolution version

Wind rose