Daily Report for 30th December 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 5.4 °C (+2.1) 01:07 3.2 °C (-0.4) 13.2 °C (+9.9), 2021 -1.4 °C (-4.7), 2014
Maximum Temperature 13.7 °C (+5.9) 14:05 7.8 °C (-0.3) 14.5 °C (+6.7), 2021 4.1 °C (-3.7), 2009
Mean Temperature 10.7 °C (+4.0) 5.6 °C (-0.4) 13.9 °C, 2021 1.3 °C, 2014
Minimum Humidity 72% 16:27 79% 98%, 2009 53%, 2015
Maximum Humidity 97% 04:22 94% 98%, 2009 81%, 2012
Mean Humidity 83% 88% 98%, 2009 72%, 2015
Minimum Pressure 989 hPa 05:01 1008 hPa 1035 hPa, 2014 989 hPa, 2017
Maximum Pressure 1002 hPa 19:31 1020 hPa 1042 hPa, 2014 998 hPa, 2009
Mean Pressure 996 hPa 1014 hPa 1038 hPa, 2014 994 hPa, 2009
Mean Wind Speed 9.1 mph (+4.0) 5.7 mph (+0.6) 11.5 mph, 2015 1.7 mph, 2016
Maximum Wind Speed 19.5 mph 13:54 13.6 mph 27.5 mph, 2013 5.6 mph, 2016
Maximum Gust 32.3 mph 13:24 22.0 mph 36.9 mph, 2013 7.3 mph, 2016
Mean Wind Direction SW
Rainfall 4.4 mm 90.9 mm (165%) 6.3 mm, 2009
Maximum Hourly Rain 1.8 mm 01:34 3.1 mm, 2015
Maximum 10-min Rain 0.4 mm 01:18 1.1 mm, 2015
Maximum Rain Rate 3.3 mm/h 01:22 36 mm/h, 2015
Minimum Dew Point 2.4 °C 23:37 1.3 °C 11.1 °C, 2021 -2.3 °C, 2014
Maximum Dew Point 10.0 °C 06:04 5.9 °C 12.8 °C, 2021 2.2 °C, 2020
Mean Dew Point 7.9 °C 3.6 °C 12.0 °C, 2021 -0.0 °C, 2014
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 4.7 °C * 21:39 3.7 °C 12.4 °C, 2021 -1.4 °C, 2014
Day Maximum (09-21) 13.7 °C 14:05 7.4 °C 14.5 °C, 2021 4.1 °C, 2009
Max 10m Temp Rise 0.5 °C 03:37 0.3 °C 0.5 °C, 2009 0.1 °C, 2010
Max 1hr Temp Rise 1.8 °C 03:50 1.1 °C 1.9 °C, 2022 0.3 °C, 2010
Max 1hr Hum Rise 9% 00:49 5% 10%, 2015 0%, 2009
Max 10m Temp Fall 0.3 °C 22:19 0.4 °C 0.5 °C, 2009 0.2 °C, 2010
Max 1hr Temp Fall 0.9 °C 22:22 1.1 °C 1.7 °C, 2020 0.3 °C, 2018
Max 1hr Hum Fall 9% 06:45 6% 13%, 2013 0%, 2009
Max 10m Wind Speed 15.4 mph 15:08 10.7 mph 18.6 mph, 2013 4.5 mph, 2016
Minimum Feels-like 1.4 °C 01:28 -1.3 °C 15.4 °C, 2021 -5.6 °C, 2014
Maximum Feels-like 14.7 °C 13:52 7.4 °C 17.1 °C, 2021 4.1 °C, 2009
Mean Feels-like 10.4 °C 3.2 °C 16.2 °C, 2021 -1.0 °C, 2014
Air-frost Hrs 0 hrs 1.0 hrs 8 hrs, 2014 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 8.3 °C (+3.8) 4.6 °C (+0.1) 8.3 °C (+3.8), 2017 1.3 °C (-3.2), 2021
Humidity Range 25% 15% 36%, 2015 0%, 2009
Pressure Range 13 hPa 12 hPa 21 hPa, 2023 2 hPa, 2018
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0.5 [7%]61 hrs (96%) [29%] 6 [85%], 2019 0 [0%], 2009
Wet Hours 6
[Mean rain rate: 0.7 mm/h]
78 hrs (130%) [11%] 15, 2009 0, 2012
Cloud Cover Mostly Cloudy with periods of Partly Cloudy
Events None
Comments overnight & 21- Rain
Extra Comments
Issues Server loss 00-01
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 30th December 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

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose