Daily Report for 28th September 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 14.1 °C (+3.7) 22:48 10.8 °C (-0.8) 15.4 °C (+5.0), 2023 6.3 °C (-4.1), 2022
Maximum Temperature 19.1 °C (+1.9) 15:02 18.5 °C (-0.6) 24.9 °C (+7.7), 2011 13.8 °C (-3.4), 2022
Mean Temperature 16.4 °C (+2.8) 14.5 °C (-0.7) 18.6 °C, 2011 9.4 °C, 2022
Minimum Humidity 64% 16:46 60% 77%, 2010 47%, 2018
Maximum Humidity 96% 06:21 92% 98%, 2011 84%, 2016
Mean Humidity 85% 79% 90%, 2010 68%, 2018
Minimum Pressure 1015 hPa 05:01 1010 hPa 1035 hPa, 2015 1001 hPa, 2022
Maximum Pressure 1020 hPa 20:46 1016 hPa 1037 hPa, 2015 1002 hPa, 2022
Mean Pressure 1018 hPa 1013 hPa 1036 hPa, 2015 1001 hPa, 2022
Mean Wind Speed 4.1 mph (+0.2) 4.4 mph (+0.5) 9.8 mph, 2016 1.5 mph, 2010
Maximum Wind Speed 9.4 mph 19:33 12.3 mph 21.5 mph, 2016 5.6 mph, 2010
Maximum Gust 16.1 mph 02:29 19.2 mph 30.6 mph, 2016 7.4 mph, 2010
Mean Wind Direction SW
Rainfall 8.1 mm 57.0 mm (122%) 10.8 mm, 2021
Maximum Hourly Rain 3.3 mm 02:37 6.9 mm, 2021
Maximum 10-min Rain 2.4 mm 02:37 3.3 mm, 2021
Maximum Rain Rate 40 mm/h 02:33 60 mm/h, 2021
Minimum Dew Point 11.7 °C 16:57 8.5 °C 12.6 °C, 2010 4.3 °C, 2018
Maximum Dew Point 15.7 °C 08:57 13.0 °C 18.1 °C, 2011 8.3 °C, 2022
Mean Dew Point 13.8 °C 10.6 °C 14.1 °C, 2014 6.5 °C, 2022
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 15.4 °C * 00:29 11.0 °C 15.4 °C, 2017 6.3 °C, 2022
Day Maximum (09-21) 19.1 °C 15:02 18.5 °C 24.9 °C, 2011 13.8 °C, 2022
Max 10m Temp Rise 0.5 °C 12:42 0.6 °C 0.7 °C, 2011 0.3 °C, 2010
Max 1hr Temp Rise 1.7 °C 12:49 2.0 °C 3.4 °C, 2011 1.0 °C, 2019
Max 1hr Hum Rise 8% 19:42 11% 14%, 2012 4%, 2010
Max 10m Temp Fall 0.3 °C 18:35 0.6 °C 0.8 °C, 2012 0.2 °C, 2010
Max 1hr Temp Fall 1.3 °C 19:15 1.7 °C 2.6 °C, 2022 0.7 °C, 2010
Max 1hr Hum Fall 12% 13:09 11% 21%, 2015 4%, 2023
Max 10m Wind Speed 6.9 mph 02:37 9.1 mph 15.9 mph, 2016 4.0 mph, 2010
Minimum Feels-like 16.4 °C 22:39 11.1 °C 17.6 °C, 2023 3.4 °C, 2022
Maximum Feels-like 22.0 °C 14:54 20.6 °C 29.0 °C, 2011 14.1 °C, 2022
Mean Feels-like 19.7 °C 16.1 °C 21.9 °C, 2011 8.8 °C, 2022
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.0 °C (-1.8) 7.7 °C (+0.2) 12.3 °C (+5.5), 2011 3.7 °C (-3.1), 2023
Humidity Range 32% 33% 47%, 2011 19%, 2010
Pressure Range 5 hPa 6 hPa 9 hPa, 2021 2 hPa, 2022
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 4 [37%]112 hrs (81%) [35%] 10.6 [99%], 2011 0.1 [1%], 2010
Wet Hours 6
[Mean rain rate: 1.3 mm/h]
49 hrs (127%) [7.2%] 6, 2017 0, 2009
Cloud Cover am: Mostly Cloudy
pm: Partly Cloudy
Events None
Comments -07 Rain
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 28th 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