Daily Report for 8th September 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 12.4 °C (+0.1) 23:37 11.6 °C (-0.9) 17.4 °C (+5.1), 2023 6.9 °C (-5.4), 2019
Maximum Temperature 17.9 °C (-2.5) 17:34 20.0 °C (-0.7) 29.7 °C (+9.3), 2023 16.0 °C (-4.4), 2015
Mean Temperature 15.3 °C (-1.2) 16.0 °C (-0.8) 23.2 °C, 2023 12.1 °C, 2019
Minimum Humidity 70% 18:13 58% 80%, 2022 24%, 2012
Maximum Humidity 93% 08:26 90% 97%, 2022 82%, 2016
Mean Humidity 84% 75% 91%, 2022 54%, 2012
Minimum Pressure 996 hPa 21:45 1011 hPa 1025 hPa, 2015 996 hPa, 2017
Maximum Pressure 1007 hPa 00:30 1018 hPa 1031 hPa, 2015 1007 hPa, 2017
Mean Pressure 1000 hPa 1015 hPa 1028 hPa, 2015 1000 hPa, 2017
Mean Wind Speed 5.8 mph (+1.9) 4.0 mph (+0.1) 6.6 mph, 2016 0.7 mph, 2024
Maximum Wind Speed 16.2 mph 00:07 12.2 mph 22.3 mph, 2016 5.9 mph, 2014
Maximum Gust 23.0 mph 00:03 18.4 mph 33.9 mph, 2016 7.6 mph, 2014
Mean Wind Direction WSW
Rainfall 5.7 mm 15.9 mm (119%) 11.8 mm, 2024
Maximum Hourly Rain 2.2 mm 12:50 6.0 mm, 2024
Maximum 10-min Rain 0.7 mm 12:37 4.1 mm, 2010
Maximum Rain Rate 13 mm/h 07:57 50 mm/h, 2010
Minimum Dew Point 10.3 °C 20:42 8.7 °C 16.1 °C, 2023 4.0 °C, 2012
Maximum Dew Point 14.6 °C 14:09 13.9 °C 21.7 °C, 2023 8.9 °C, 2019
Mean Dew Point 12.6 °C 11.2 °C 18.6 °C, 2023 6.5 °C, 2019
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 14.4 °C * 08:13 12.0 °C 17.8 °C, 2016 6.9 °C, 2019
Day Maximum (09-21) 17.9 °C 17:34 20.0 °C 29.7 °C, 2023 16.0 °C, 2015
Max 10m Temp Rise 0.3 °C 15:56 0.6 °C 1.2 °C, 2012 0.3 °C, 2011
Max 1hr Temp Rise 1.0 °C 16:08 1.9 °C 4.9 °C, 2012 1.0 °C, 2017
Max 1hr Hum Rise 8% 19:17 9% 16%, 2013 4%, 2020
Max 10m Temp Fall 0.8 °C 18:24 0.7 °C 1.4 °C, 2013 0.3 °C, 2015
Max 1hr Temp Fall 2.9 °C 19:06 1.7 °C 4.0 °C, 2012 1.1 °C, 2018
Max 1hr Hum Fall 10% 16:06 9% 18%, 2013 5%, 2015
Max 10m Wind Speed 11.8 mph 00:16 9.0 mph 17.7 mph, 2016 4.1 mph, 2014
Minimum Feels-like 14.2 °C 23:35 12.6 °C 22.1 °C, 2023 5.3 °C, 2019
Maximum Feels-like 20.8 °C 17:22 22.8 °C 38.2 °C, 2023 17.1 °C, 2015
Mean Feels-like 17.9 °C 18.0 °C 29.8 °C, 2023 11.8 °C, 2019
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.5 °C (-2.6) 8.4 °C (+0.2) 17.2 °C (+9.1), 2012 5.3 °C (-2.8), 2022
Humidity Range 23% 32% 60%, 2012 17%, 2022
Pressure Range 11 hPa 7 hPa 11 hPa, 2017 2 hPa, 2023
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 1.2 [10%]30 hrs (72%) [31%] 11.7 [98%], 2014 0.3 [3%], 2010
Wet Hours 6
[Mean rain rate: 1.0 mm/h]
21 hrs (192%) [11%] 6, 2017 0, 2009
Cloud Cover am: Overcast
pm: Overcast transitioned to Partly Cloudy
Events None
Comments 06-14 Rain spells
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 8th September 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