Daily Report for 15th December 2015

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 9.4 °C (+5.8) 00:18 8.8 °C (+5.0) 10.3 °C (+6.7), 2021 -5.1 °C (-8.7), 2022
Maximum Temperature 13.6 °C (+5.6) 23:56 12.7 °C (+4.2) 13.6 °C (+5.6), 2015 0.4 °C (-7.6), 2022
Mean Temperature 11.6 °C (+5.7) 10.9 °C (+4.6) 11.9 °C, 2021 -2.1 °C, 2022
Minimum Humidity 89% 00:03 72% 90%, 2013 65%, 2011
Maximum Humidity 92% 07:34 89% 97%, 2010 83%, 2016
Mean Humidity 91% 82% 95%, 2013 75%, 2011
Minimum Pressure 1014 hPa 22:22 1017 hPa 1030 hPa, 2023 984 hPa, 2012
Maximum Pressure 1017 hPa 08:42 1024 hPa 1040 hPa, 2023 997 hPa, 2012
Mean Pressure 1015 hPa 1021 hPa 1037 hPa, 2023 991 hPa, 2012
Mean Wind Speed 3.0 mph (-2.1) 7.1 mph (+2.0) 8.6 mph, 2018 2.2 mph, 2009
Maximum Wind Speed 11.4 mph 13:41 17.4 mph 19.2 mph, 2011 6.9 mph, 2009
Maximum Gust 15.4 mph 13:40 25.4 mph 30.0 mph, 2019 10.7 mph, 2009
Mean Wind Direction SSE
Rainfall 6.1 mm 26.8 mm (97%) 11.2 mm, 2018
Maximum Hourly Rain 2.4 mm 18:24 4.2 mm, 2019
Maximum 10-min Rain 0.9 mm 19:22 2.4 mm, 2019
Maximum Rain Rate 24 mm/h 19:21 26 mm/h, 2019
Minimum Dew Point 7.7 °C 00:03 5.2 °C 8.4 °C, 2021 -6.6 °C, 2022
Maximum Dew Point 12.2 °C 23:50 10.1 °C 12.2 °C, 2015 -1.7 °C, 2022
Mean Dew Point 10.2 °C 7.9 °C 10.3 °C, 2013 -4.2 °C, 2022
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 9.4 °C 00:18 9.5 °C 10.3 °C, 2021 -5.1 °C, 2022
Day Maximum (09-21) * 12.6 °C * 20:55 12.4 °C 12.9 °C, 2021 0.4 °C, 2022
Max 10m Temp Rise 0.2 °C 01:06 0.3 °C 0.5 °C, 2009 0.2 °C, 2015
Max 1hr Temp Rise 0.5 °C 01:21 1.0 °C 1.7 °C, 2022 0.4 °C, 2021
Max 1hr Hum Rise 2% 01:05 5% 9%, 2011 2%, 2013
Max 10m Temp Fall 0.1 °C 15:03 0.4 °C 1.2 °C, 2019 0.1 °C, 2015
Max 1hr Temp Fall 0.2 °C 15:03 1.0 °C 2.3 °C, 2019 0.2 °C, 2015
Max 1hr Hum Fall 1% 02:04 5% 7%, 2009 1%, 2015
Max 10m Wind Speed 8.1 mph 12:04 12.9 mph 14.3 mph, 2018 4.9 mph, 2009
Minimum Feels-like 8.7 °C 00:35 7.1 °C 11.2 °C, 2021 -10.5 °C, 2022
Maximum Feels-like 16.0 °C 23:53 13.9 °C 16.0 °C, 2015 0.4 °C, 2022
Mean Feels-like 12.9 °C 11.0 °C 12.9 °C, 2015 -4.3 °C, 2022
Air-frost Hrs 0 hrs 0 hrs 22 hrs, 2022 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 4.2 °C (-0.2) 4.0 °C (-0.8) 5.9 °C (+1.5), 2014 2.3 °C (-2.1), 2009
Humidity Range 3% 17% 29%, 2018 3%, 2015
Pressure Range 3 hPa 8 hPa 21 hPa, 2017 2 hPa, 2009
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0 [0%]16 hrs (51%) [15%] 7 [100%], 2022 0 [0%], 2010
Wet Hours 6
[Mean rain rate: 1.0 mm/h]
43 hrs (143%) [12%] 7, 2018 0, 2009
Cloud Cover Overcast
Events None
Comments 15- Rain/Showers
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 15th December 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