Daily Report for 20th February 2018

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 4.6 °C (+1.7) 23:54 1.2 °C (-1.6) 11.3 °C (+8.4), 2021 -2.0 °C (-4.9), 2012
Maximum Temperature 8.9 °C (+0.7) 00:00 7.1 °C (-0.9) 17.1 °C (+8.9), 2017 4.2 °C (-4.0), 2013
Mean Temperature 7.6 °C (+1.2) 4.4 °C (-1.3) 13.1 °C, 2021 1.0 °C, 2010
Minimum Humidity 69% 14:42 68% 93%, 2011 44%, 2012
Maximum Humidity 96% 03:58 92% 98%, 2011 78%, 2012
Mean Humidity 86% 82% 95%, 2011 63%, 2012
Minimum Pressure 1017 hPa 01:45 1010 hPa 1030 hPa, 2012 994 hPa, 2022
Maximum Pressure 1025 hPa 23:15 1019 hPa 1033 hPa, 2012 998 hPa, 2010
Mean Pressure 1020 hPa 1014 hPa 1032 hPa, 2012 996 hPa, 2010
Mean Wind Speed 6.8 mph (+1.7) 5.5 mph (+0.4) 13.3 mph, 2022 2.1 mph, 2009
Maximum Wind Speed 17.6 mph 18:12 14.2 mph 26.9 mph, 2022 9.2 mph, 2010
Maximum Gust 27.6 mph 18:13 22.2 mph 38.8 mph, 2022 12.1 mph, 2010
Mean Wind Direction N
Rainfall 0.4 mm 32.2 mm (100%) 6.7 mm, 2022
Maximum Hourly Rain 0.2 mm 6.2 mm, 2022
Maximum 10-min Rain 0.2 mm 3.4 mm, 2022
Maximum Rain Rate n/a 60, 2022
Minimum Dew Point 2.0 °C 23:53 -1.1 °C 7.6 °C, 2021 -6.8 °C, 2012
Maximum Dew Point 8.0 °C 00:00 4.2 °C 12.2 °C, 2017 1.1 °C, 2012
Mean Dew Point 5.3 °C 1.5 °C 9.8 °C, 2025 -2.9 °C, 2012
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 7.9 °C * 05:29 2.1 °C 10.9 °C, 2021 -2.0 °C, 2012
Day Maximum (09-21) * 8.8 °C * 15:07 6.8 °C 17.1 °C, 2017 4.2 °C, 2013
Max 10m Temp Rise 0.5 °C 13:57 0.5 °C 0.8 °C, 2009 0.1 °C, 2011
Max 1hr Temp Rise 0.7 °C 12:11 1.6 °C 2.8 °C, 2012 0.3 °C, 2011
Max 1hr Hum Rise 13% 15:46 8% 13%, 2014 1%, 2011
Max 10m Temp Fall 0.6 °C 15:40 0.5 °C 2.9 °C, 2022 0.1 °C, 2011
Max 1hr Temp Fall 1.5 °C 16:06 1.2 °C 4.2 °C, 2022 0.3 °C, 2011
Max 1hr Hum Fall 10% 10:42 8% 21%, 2009 1%, 2011
Max 10m Wind Speed 15.3 mph 18:13 11.0 mph 21.5 mph, 2022 5.7 mph, 2010
Minimum Feels-like 0.2 °C 23:41 -2.8 °C 11.6 °C, 2021 -5.7 °C, 2012
Maximum Feels-like 9.1 °C 00:21 6.1 °C 19.4 °C, 2017 3.3 °C, 2013
Mean Feels-like 4.9 °C 1.5 °C 13.6 °C, 2017 -0.6 °C, 2013
Air-frost Hrs 0 hrs 1 hrs 10 hrs, 2010 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 4.3 °C (-1.1) 5.9 °C (+0.8) 10.3 °C (+4.9), 2012 1.5 °C (-3.9), 2011
Humidity Range 27% 25% 44%, 2009 5%, 2011
Pressure Range 8 hPa 9 hPa 18 hPa, 2022 3 hPa, 2009
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 1 [11%]58 hrs (107%) [33%] 6 [65%], 2010 0 [0%], 2011
Wet Hours 1
[Mean rain rate: 0.4 mm/h]		50 hrs (133%) [10%] 6, 2016 , 2009
Cloud Cover Overcast with periods of Partly Cloudy
Events None
Comments 09, 1530 Showers
Extra Comments
Issues None known
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 20th February 2018.
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.
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Daily Graph of Conditions

day graph

Webcam Summary of Cloud Conditions

daycamsumLarge resolution version

Wind rose