Daily Report for 12th May 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 12.6 °C (+4.1) 02:08 7.9 °C (-0.0) 12.6 °C (+4.1), 2017 1.0 °C (-7.5), 2010
Maximum Temperature 18.8 °C (+1.5) 16:35 15.5 °C (-1.3) 25.5 °C (+8.2), 2024 11.4 °C (-5.9), 2010
Mean Temperature 15.1 °C (+2.8) 11.4 °C (-0.7) 19.2 °C, 2024 6.9 °C, 2010
Minimum Humidity 59% 19:07 55% 79%, 2023 34%, 2009
Maximum Humidity 86% 05:39 81% 94%, 2016 74%, 2009
Mean Humidity 75% 69% 89%, 2023 52%, 2015
Minimum Pressure 993 hPa 03:13 1011 hPa 1033 hPa, 2012 993 hPa, 2017
Maximum Pressure 1002 hPa 23:47 1019 hPa 1040 hPa, 2019 1002 hPa, 2017
Mean Pressure 996 hPa 1014 hPa 1036 hPa, 2019 996 hPa, 2017
Mean Wind Speed 4.7 mph (+0.0) 4.4 mph (-0.3) 7.1 mph, 2015 1.9 mph, 2020
Maximum Wind Speed 13.8 mph 16:05 11.2 mph 17.8 mph, 2015 7.6 mph, 2010
Maximum Gust 21.0 mph 16:05 17.6 mph 27.5 mph, 2015 10.9 mph, 2010
Mean Wind Direction SSW
Rainfall 1.4 mm 9.8 mm (55%) 7.3 mm, 2018
Maximum Hourly Rain 0.6 mm 04:07 2.6 mm, 2018
Maximum 10-min Rain 0.4 mm 00:10 1.9 mm, 2014
Maximum Rain Rate 0.7 mm/h 04:02 54 mm/h, 2014
Minimum Dew Point 8.0 °C 22:18 3.5 °C 10.4 °C, 2016 -2.2 °C, 2010
Maximum Dew Point 12.8 °C 13:43 7.8 °C 16.1 °C, 2024 2.8 °C, 2010
Mean Dew Point 10.5 °C 5.7 °C 12.8 °C, 2024 0.1 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 12.6 °C 02:08 8.0 °C 12.6 °C, 2017 1.0 °C, 2010
Day Maximum (09-21) 18.8 °C 16:35 15.5 °C 25.5 °C, 2024 11.4 °C, 2010
Max 10m Temp Rise 0.7 °C 15:01 0.6 °C 0.9 °C, 2019 0.4 °C, 2018
Max 1hr Temp Rise 1.4 °C 15:19 1.8 °C 4.5 °C, 2019 1.1 °C, 2018
Max 1hr Hum Rise 6% 22:40 8% 18%, 2013 6%, 2009
Max 10m Temp Fall 0.4 °C 20:19 0.4 °C 1.1 °C, 2014 0.4 °C, 2009
Max 1hr Temp Fall 1.5 °C 20:50 1.4 °C 3.1 °C, 2016 1.3 °C, 2018
Max 1hr Hum Fall 10% 15:57 10% 22%, 2019 6%, 2023
Max 10m Wind Speed 11.2 mph 16:28 8.5 mph 14.9 mph, 2015 5.4 mph, 2020
Minimum Feels-like 13.4 °C 23:55 5.7 °C 14.1 °C, 2016 -1.0 °C, 2010
Maximum Feels-like 20.9 °C 15:19 15.8 °C 29.4 °C, 2024 11.4 °C, 2010
Mean Feels-like 16.6 °C 11.0 °C 22.0 °C, 2024 6.0 °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 6.2 °C (-2.6) 7.7 °C (-1.3) 14.1 °C (+5.3), 2020 1.4 °C (-7.4), 2016
Humidity Range 27% 26% 58%, 2019 15%, 2023
Pressure Range 9 hPa 8 hPa 9 hPa, 2019 2 hPa, 2018
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2.4 [17%]45 hrs (64%) [28%] 12 [86%], 2016 0.2 [1%], 2018
Wet Hours 2
[Mean rain rate: 0.7 mm/h]
9 hrs (58%) [3.1%] 8, 2018 0, 2009
Cloud Cover am: Overcast or Mostly Cloudy
pm: Partly Cloudy
Events None
Comments o.night 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 12th 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