Daily Report for 9th May 2015

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 10.9 °C (+2.8) 23:59 8.9 °C (+1.2) 14.2 °C (+6.1), 2016 5.9 °C (-2.2), 2022
Maximum Temperature 17.6 °C (+0.6) 16:10 16.3 °C (-0.3) 24.8 °C (+7.8), 2016 11.5 °C (-5.5), 2010
Mean Temperature 14.0 °C (+1.7) 12.4 °C (+0.4) 18.5 °C, 2016 8.4 °C, 2010
Minimum Humidity 37% 15:07 45% 72%, 2012 31%, 2025
Maximum Humidity 84% 00:55 88% 96%, 2019 74%, 2017
Mean Humidity 60% 68% 90%, 2012 56%, 2016
Minimum Pressure 1010 hPa 01:35 1002 hPa 1025 hPa, 2024 993 hPa, 2019
Maximum Pressure 1023 hPa 23:47 1011 hPa 1030 hPa, 2024 1002 hPa, 2021
Mean Pressure 1015 hPa 1006 hPa 1028 hPa, 2024 998 hPa, 2019
Mean Wind Speed 8.9 mph (+4.2) 7.8 mph (+3.1) 10.0 mph, 2013 2.4 mph, 2019
Maximum Wind Speed 21.0 mph 14:00 17.9 mph 24.6 mph, 2013 8.2 mph, 2024
Maximum Gust 32.0 mph 14:00 27.6 mph 38.4 mph, 2013 11.5 mph, 2024
Mean Wind Direction WSW
Rainfall 0.0 mm 23.8 mm (178%) 10.4 mm, 2023
Maximum Hourly Rain n/a 4.3, 2023
Maximum 10-min Rain n/a 1.5, 2023
Maximum Rain Rate n/a 14.4, 2023
Minimum Dew Point 2.1 °C 23:15 2.7 °C 10.3 °C, 2023 0.5 °C, 2025
Maximum Dew Point 10.8 °C 00:05 10.0 °C 14.9 °C, 2024 4.3 °C, 2017
Mean Dew Point 6.0 °C 6.2 °C 12.2 °C, 2023 2.6 °C, 2017
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 11.7 °C * 06:19 9.0 °C 14.2 °C, 2016 5.9 °C, 2022
Day Maximum (09-21) 17.6 °C 16:10 16.3 °C 24.8 °C, 2016 11.5 °C, 2010
Max 10m Temp Rise 0.6 °C 14:32 0.6 °C 1.0 °C, 2020 0.5 °C, 2010
Max 1hr Temp Rise 1.8 °C 14:07 1.9 °C 4.8 °C, 2020 1.5 °C, 2023
Max 1hr Hum Rise 5% 23:36 9% 28%, 2013 5%, 2015
Max 10m Temp Fall 0.5 °C 15:12 0.5 °C 1.2 °C, 2013 0.3 °C, 2010
Max 1hr Temp Fall 1.4 °C 20:41 1.3 °C 3.3 °C, 2023 1.1 °C, 2012
Max 1hr Hum Fall 12% 15:05 14% 24%, 2013 6%, 2012
Max 10m Wind Speed 16.1 mph 00:10 13.8 mph 18.7 mph, 2013 5.8 mph, 2024
Minimum Feels-like 10.9 °C 23:59 6.6 °C 14.2 °C, 2016 2.8 °C, 2025
Maximum Feels-like 17.6 °C 16:00 16.9 °C 27.4 °C, 2024 11.5 °C, 2010
Mean Feels-like 14.3 °C 12.3 °C 20.1 °C, 2024 7.1 °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 6.7 °C (-2.2) 7.4 °C (-1.5) 15.9 °C (+7.0), 2022 4.5 °C (-4.4), 2012
Humidity Range 47% 43% 58%, 2025 23%, 2012
Pressure Range 13 hPa 9 hPa 14 hPa, 2017 2 hPa, 2016
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 4 [29%]31 hrs (59%) [25%] 12.5 [90%], 2011 0 [0%], 2012
Wet Hours 018 hrs (151%) [8.1%] 7, 2023 0, 2009
Cloud Cover am: Mostly Cloudy
pm: Partly Cloudy
Events None
Comments -
Extra Comments
Issues wind sensor out of battery; data reconstructed
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 9th May 2015.
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