Daily Report for 18th January 2017

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature -3.3 °C (-6.3) 06:39 1.9 °C (-1.2) 7.6 °C (+4.6), 2014 -4.3 °C (-7.3), 2024
Maximum Temperature 4.0 °C (-3.8) 14:51 7.4 °C (-0.4) 11.9 °C (+4.1), 2012 1.8 °C (-6.0), 2013
Mean Temperature -0.1 °C (-5.1) 4.7 °C (-0.8) 9.3 °C, 2012 -1.4 °C, 2024
Minimum Humidity 53% 16:02 68% 95%, 2010 50%, 2009
Maximum Humidity 82% 10:25 83% 98%, 2010 82%, 2017
Mean Humidity 70% 77% 98%, 2010 70%, 2017
Minimum Pressure 1036 hPa 22:12 1019 hPa 1036 hPa, 2017 989 hPa, 2014
Maximum Pressure 1039 hPa 07:49 1027 hPa 1040 hPa, 2022 993 hPa, 2014
Mean Pressure 1038 hPa 1023 hPa 1038 hPa, 2017 990 hPa, 2014
Mean Wind Speed 0.2 mph (-5.0) 3.9 mph (-1.3) 10.4 mph, 2018 0.2 mph, 2017
Maximum Wind Speed 3.8 mph 11:47 11.2 mph 31.0 mph, 2018 3.8 mph, 2017
Maximum Gust 5.2 mph 10:49 16.4 mph 47.2 mph, 2018 5.2 mph, 2017
Mean Wind Direction S
Rainfall 0.0 mm 48.0 mm (140%) 7.6 mm, 2011
Maximum Hourly Rain n/a 3, 2009
Maximum 10-min Rain n/a 1.1, 2011
Maximum Rain Rate n/a 10, 2011
Minimum Dew Point -6.8 °C 05:51 -1.9 °C 4.8 °C, 2014 -7.5 °C, 2024
Maximum Dew Point -1.8 °C 12:00 3.8 °C 11.1 °C, 2012 -2.3 °C, 2013
Mean Dew Point -5.0 °C 1.0 °C 8.4 °C, 2012 -5.0 °C, 2017
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) -3.3 °C 06:39 3.0 °C 6.8 °C, 2014 -4.3 °C, 2024
Day Maximum (09-21) 4.0 °C 14:51 7.2 °C 11.9 °C, 2012 -0.8 °C, 2013
Max 10m Temp Rise 0.5 °C 09:28 0.3 °C 0.9 °C, 2019 0.1 °C, 2013
Max 1hr Temp Rise 1.8 °C 10:20 1.2 °C 3.8 °C, 2019 0.4 °C, 2013
Max 1hr Hum Rise 5% 18:45 4% 6%, 2013 2%, 2010
Max 10m Temp Fall 0.4 °C 18:18 0.5 °C 0.4 °C, 2017 0.1 °C, 2012
Max 1hr Temp Fall 1.5 °C 18:34 1.4 °C 1.8 °C, 2018 0.3 °C, 2012
Max 1hr Hum Fall 9% 12:39 6% 15%, 2018 0%, 2010
Max 10m Wind Speed 2.7 mph 11:39 8.5 mph 23.3 mph, 2018 2.7 mph, 2017
Minimum Feels-like -5.3 °C 06:16 -1.8 °C 4.7 °C, 2014 -10.2 °C, 2024
Maximum Feels-like 4.0 °C 14:28 7.0 °C 13.7 °C, 2012 -0.4 °C, 2013
Mean Feels-like -0.2 °C 2.9 °C 8.9 °C, 2012 -5.3 °C, 2013
Air-frost Hrs 11 hrs 2 hrs 18 hrs, 2013 0 hrs, 2010
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 7.3 °C (+2.5) 5.5 °C (+0.8) 8.3 °C (+3.5), 2019 2.2 °C (-2.6), 2014
Humidity Range 29% 15% 44%, 2009 3%, 2010
Pressure Range 3 hPa 8 hPa 21 hPa, 2024 1 hPa, 2010
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 7.5 [99%]36 hrs (91%) [27%] 7.6 [101%], 2020 0 [0%], 2012
Wet Hours 064 hrs (163%) [15%] 10, 2013 , 2009
Cloud Cover Sunny with periods of Mostly Sunny
Events Air Frost
Maximum possible sunshine
Comments -
Extra Comments mysterious false tips removed
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 18th January 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